- test-drb@ccmp.vtda.org - classiccmp.org

PMI memory on an -11/93 (Was: Installing an operating system on an 11/83)

by jnc＠mercury.lcs.mit.edu

> From: Christian Gauger-Cosgrove > From the KDJ11-E module user's guide ... the solder-side of the CD > fingers is left unpopulated, but for the +5 and ground pins. > The only PMI compatible option then would be the KTJ11-B UNIBUS adapter. I forget how the -11/84-94 backplane is wired (it's wierd - the QBUS CD slots are bussed together in a group, they're not in pairs like an ordinary Q/CD backplane - but I forget the fine details), but how does the PMI get from the CPU to the KTJ11, then? I know on the same backplane, it supports PMI memory cards with the KDJ11-B. And speaking of the KDJ11-B, I just looked at one, and _it_ doesn't have any lands on the C/D connectors, side 2, either! Probably because the PMI only uses side 1 lands: https://gunkies.org/wiki/Private_Memory_Interconnect#Pinout Given that the KDJ11-E can do master-slave cycles through the KTJ11-B (to read UNIBUS device registers), it has to be able to do master-slave cycles on the PMI. What I don't know is whether, on a 2MB KDJ11-E, it will try and send memory reads for locations > 2MB out the PMI, or whether all reads below the UNIBUS address space (in 22-bit address terms) are sent to the local memory _only_. Someone with a 2MB KDJ11-E should try it... Noel

3 years, 2 months

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Seeking paper tape punch

by jfoust＠threedee.com

At 08:24 PM 2/21/2022, Steve Malikoff via cctalk wrote: >Consumer-grade CNC stencil cutters are fine at cutting plastic sheet and should be ok with film stock. >My ptap2dxf (latest version 1.3) will produce output to cut tapes for ... Meaning the Cricut kind of device? Clever! So it works for short sections? Has anyone ever made a Cricut style cutter that has a continuous feed of tape? Why did you pick AutoCAD DXF as compared to Adobe Illustrator? At 07:02 PM 2/21/2022, Paul Koning via cctalk wrote: >I understand there is a group called "Green keys" -- ham radio operators who use old "teletype" machines -- which in that community means wny sort of keyboard telex-type machine, not necessarily made by Teletype Co. though US ones often are. 5 bit machines are common in that crowd, some 8 bit machines also appear. I haven't participated, but I would think that you might find pointers to options there. GreenKeys mailing list Home: http://mailman.qth.net/mailman/listinfo/greenkeys Help: http://mailman.qth.net/mmfaq.htm Post: mailto:GreenKeys at mailman.qth.net They can be very helpful. They tend to focus on other non-33 teletypes. The list can be a good place to find out about people selling or giving away equipment, though. The collectors of the heavy, older, machined teletypes tend to shake their heads at the high prices and popularity of the light-duty cheaper punched-metal 33s. You might find someone giving away a bulky heavy ASR 28 that handles 5-level tape... https://www.telegramcableco.com/teletype-model-28-asr.html https://en.wikipedia.org/wiki/Teletype_Model_28 Less common to find them giving away a 33 because the computer nuts will pay $xxx to $x,xxx for them. - John

3 years, 2 months

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PMI memory on an -11/93 (Was: Installing an operating system on an 11/83)

by jnc＠mercury.lcs.mit.edu

> From: Bill Gunshannon > Just wish I could get some PMI memory for that 93. ?? The KDJ11-E in the -11/93 comes with a minimum of 2MB on the CPU card. That's enough for almost 16 maximum-sized processes (assuming they aren't sharing program texts - almost double that, if they are). Does one really need more than that for vintage retro use? Besides, the on-board memory operates at full speed (same as cache memory on the KDJ11-B); even if you added PMI memory, the KDJ11-E has no cache, so it would be a _lot_ slower than the on-board memory. Noel PS: Can people _please_ trim messages they are replying to, so we don't all have to scroll down past a bunch of irrelevant drek? Thank you.

3 years, 2 months

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Installing an operating system on an 11/83

by rodsmallwood52＠btinternet.com

Hi ? I have built an 11/83 in a BA23 box. ? It has a KDJ-11B, 2mB PMI memory, an RQDX3 with an RX50 attached, Plus a CMD CQD 220A Disk controller with a digital RH18A 2Gig SCSI drive attached. Diag sees drive as RA82. It boots and runs the diag disk and XXDP+ just fine. I do not have install distributions for any of the 11/83 operating systems. Daily driver system is a Windows 10 PC. So how do I install an operating system? Suggestions please. Thanks Rod

3 years, 2 months

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Seeking paper tape punch

by fedorkow＠mit.edu

[apologies if this is a dup, but I didn't see it coming back in any of the cctalk digests] Greetings CC-Talk, ? I've been working on a low-budget project to help to introduce students to history of computing through material we have from MIT's 1950's Whirlwind project.? The activity would have more of a hands-on feel if we could use actual paper tape. ? A simple reader is easy enough, but a punch is a bit harder.? We don't need anything "authentic", or fast, or high performance, just something fairly reliable. ?? If anyone can suggest where to find such a machine, could you let me know?? Fanuc PPR, GNT 4601/4604, and the DSI NC-2400 have been cited as possible candidates, but I don't see anything that looks like a good match on ebay. ? Thanks! /guy fedorkow

3 years, 2 months

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Seeking paper tape punch

by paulkoning＠comcast.net

> On Feb 21, 2022, at 6:07 PM, Guy Fedorkow <fedorkow at mit.edu> wrote: > > hi Paul, > Yes, I should have said -- I'm looking for a machine that can punch under control of a computer. > Whirlwind actually used seven-bit Flexowriters for reading and punching (along with a high-speed reader later on), but I think it would be even harder to find fresh seven-level tape even if a seven bit machine turned up. > I actually have been using a BRPE on loan from another contributor to this list, but it's time to return the unit, so I've started to look for alternatives. > I assume something like an ASR-33 would do the trick, although a machine without keyboard and printer might have fewer moving parts to go wrong. But I don't see many plausible choices on ebay. > If anyone can suggest other sources, I'll poke around The nice thing about an ASR33 (or other hardcopy terminal with reader/punch like a TT model 15) is that you can interface them to a computer rather easily, just hook up a UART with appropriate driver/receiver circuitry. RS232 to 20 mA (or 60mA for a Model 15) isn't totally trivial but it certainly is no big deal. And those slow machines actually have the nice benefit that it's easy for people to see the action, and to get some understanding at a gut level of how slow computers were in those days. I understand there is a group called "Green keys" -- ham radio operators who use old "teletype" machines -- which in that community means wny sort of keyboard telex-type machine, not necessarily made by Teletype Co. though US ones often are. 5 bit machines are common in that crowd, some 8 bit machines also appear. I haven't participated, but I would think that you might find pointers to options there. As for 7 bit tape media: I found out in the past year or so that there actually was such a thing as paper tape of width designed for 7 tracks, but a lot of "7 bit" paper tape work actually used 1 inch wide tape, i.e., what is normally considered 8 bit tape. For example, the Flexowriters on which I did my first programming at TU Eindhoven used a 7-bit code but on 8 bit tape. paul

3 years, 2 months

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VAX9000 unearthed

by mark.kahrs＠gmail.com

I heard Butler Lampson once exclaim that ECL design was in some ways easier than TTL. If you terminated every line, you get controlled impedances with controlled edges. This was the design philosophy for the Dorado.

3 years, 2 months

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More VT52 HV

by fritzm＠fritzm.org

So, having pulled the CRT now , I was surprised to see that the ground braids seem to be held against the aquadag by only the pressure from a couple foam blocks! In my unit these aged foams are deformed and brittle. This would seem a good thing to add to the check list for looking at these? I wonder if this explains why many of these I encountered back in the day in university terminal rooms and such were suffering from HV ?snaps?? I had always assumed it was just dust / grime / spilled cokes? :-) Also, after a closer look, I?m surmising the red goo around the anode cap to be dielectric grease put there on purpose, and not degradation of the cap itself. ?FritzM.

3 years, 2 months

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rotron caravel fan used in DEC and other cabinets

by useddec＠gmail.com

Does anyone have a video or printed procedure they can send me or point me somewhere that could help? Thanks, Paul

3 years, 2 months

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rotron caravel fan used in DEC and other cabinets

by jnc＠mercury.lcs.mit.edu

> From: Vincent Slyngstad > I had to replace one of those recently Where did you source the replacement? I need a few. Thanks! Noel

3 years, 2 months

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Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

> Neither the KD11-E nor the KD11-EA has built-in termination and pull-ups > ... I haven't yet checked, but it may be the only PDP-11 CPU of which > that is true Also the KD11-D of the -11/04. Noel

3 years, 2 months

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Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

So, I've made what I think is a significant discovery about the -11/34: > 1B _is_ necessary, but can be provided anywhere on the bus; most > UNIBUS/QBUS CPU [pullups] have it built in I was wrong. Neither the KD11-E nor the KD11-EA has built-in termination and pull-ups (those are both done with one set of components). I haven't yet checked, but it may be the only PDP-11 CPU of which that is true Without _something_ doing the latter of the above, the UNIBUS won't function at all. (The UNIBUS signal lines mostly operate as negative-logic wired-OR; the pull-ups float it high for '0', and any board pulls it low to send a '1'. No pull-ups, then..) This is almost certainly the reason that the manual calls for the use of either an M9301 ROM or M9312 ROM (which include bus termination) at the start of their UNIBUS, in slot 3 or 4 of the CPU's backplane. (The M7859 of the KY11-LB doesn't have pull-ups either; so in a system with a set of KD11-E/EA cards, and a KY11-B, and nothing else, the KY11-B won't be able to examine UNIBUS locations - even though in a system with _just_ a KY11-B, and one of M9301/M9302/M9312, and NO KD11-E/EA, the KY11-B _can_ do UNIBUS operations.) A system with just an M9302, and no M9301/M9312, will _probably_ work, even though the UNIBUS is only terminated at one end (see my previous post, about QBUS termination on one end only); the M9302 will provide the pull-ups needed for the UNIBUS to function (above). I have also made a number of interesting discoveries about the SACK turnaround; I'll put them in a reply to Fritz's message. Noel

3 years, 2 months

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SGI Indigo keyboard / mouse / converter wanted

by jules.richardson99＠gmail.com

Hi all, A friend of mine has just acquired an Indigo (R4k with XZ graphics option), but of course it's the usual story and the keyboard/rodent had been lost. In absence of the genuine items they'd still be happy with a USB converter (at least for the time being), but it seems those are difficult to come by at present, too. Does anyone happen to have a surplus converter suitable for these machines, and/or keyboard/rodent? (according to sgistuff keyboard is p/n 9500801 and mouse p/n 9150800) [side note: they mentioned a USB converter, but I'm pretty sure years ago someone had implemented an adapter to PC-friendly PS/2 parts, too. I'm sure something like would do the trick, too] thanks, Jules

3 years, 2 months

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Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

> From: Jay Jaeger > SACK turnaround capability so that the machine doesn't hang accessing > an address that doesn't respond on the UNIBUS. Umm, I think you're mixing up i) grant timeouts and ii) master-slave timeouts. All PDP-11 CPUs have master-slave timeout handling; after a short delay (10usec or so) with no SSYN (UNIBUS) or BRPLY (QBUS), they resume processing, and take an immediate trap. Most OS's (UNIX, for sure) use this when they are sizing memory. Grant timeouts are less well-documented. I think most CPUs deal with this (not receiving a SACK 'fairly quickly' in response to a grant); I think they basically just ignore t, and keep processing. (That is because there are legitimate causes for not having a grant ackknowledged; e.g. if a device is requesting an interrupt, and then just as the CPU sends out a grant, the device is reset, the device won't respond to the grant, since it's no longer trying to do an interrupt.) The 'SACK turnaround' I think is only used with system health verification; the system wants to make sure that the grant lines aren't broken anywhere. (That's because _if_ a grant line is broken, devices downstream of the break can no longer do interrupts, which generally _will_ hang the overall system, when interrupts don't work as usual.) To do this, the CPU sends an _un-requested_ grant out (on startup), and the SACK turnaround circuitry on the terminator turns it around and sends it back to the CPU; when the CPU sees that, it knows the grant line has no break. It probably caused more problems than it caught, which is my guess as to why no QBUS machine has/uses it. The -11/34 (not the /34A) has something unusual for grant timeouts, but I forget the details. I'll look it up. Noel

3 years, 2 months

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Red Hat Linux 7.2 for Alpha

by me＠larbob.org

Try these: https://mirror.rqsall.com/misc/rh-alpha/7.2/ Larkin

3 years, 2 months

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VAX9000 unearthed

by ioerg.hoppe＠gmail.com

Hi, my computer club c-c-g.de could acquire the remains of a VAX9000 ! The machine ran at the GWDG computing center in G?ttingen, Germany, around 1993. Parts of it were in stock of their museum for 20+ years. See lots of hires-pictures at https://c-c-g.de/fachartikel/359-vax-9000-ein-starker-exot (scroll to the bottom for a slide show). Joerg

3 years, 2 months

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Is The M9312 Boot Module Essential?

by robert.jarratt＠ntlworld.com

I have a PDP-11/24. I have never got very far with it because of power supply problems which I am hopeful will be resolved soon. Looking at the technical manual, it describes an M9312 bootstrap/terminator module. The machine did not come with one of these. I am not sure how the machine could have been useful without it. It did work briefly before the PSU failed and I remember getting a console prompt. So, is the M9312 essential to ever get this machine to boot up an operating system? Thanks Rob

3 years, 2 months

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DEC AXV11-C analog board

by dj.taylor4＠comcast.net

I have one of these and would like to use it, however it appears to only partially work.? Here is what I have found that works and what doesn't: 1. CSR and DBR are present and operational. 2. Jumpers set to 'factory'. 3. D/A portion works, can deposit codes in ODT and see voltages out on DAC pins that change depending on the octal value deposited in CSR+4 or +6. 4. A/D portion returns full scale code, either 3777 (2's compliment) or 7777 (offset binary) whether in the input is open or shorted to gnd. I think the problem is that the A/D inputs are not exactly protected and damage has occurred to this portion in the past. Does anyone have any info on the A/D module?? Who made it?? Can you open it up?? Does XXDP have a test for this? Doug

3 years, 2 months

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Free Stuff - Pleasanton, Calif.

by bpettitx＠comcast.net

I'm downsizing. Have to get rid of everything. The driveway is filled systems test equipment, components, parts, books, etc. Several thousand TTL chips prototyping boards. Come out and take what you. Junk Bees will be here on Tuesday for what is left. Call 925-998-9968 for directions.

3 years, 2 months

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Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

> From: Rob Jarratt > is the M9312 essential to ever get this machine to boot up an operating > system? Interesting question. I don't have my -11/24 running yet, so this reply is theoretical, not tried in practice (and as we all know, the difference between theory and practice is even larger in practice than it is in theory), but here goes. The M9312 basically provides two things: 1) UNIBUS termination, and 2) boostrap ROM. To further subdivide the former, it provides 1A) analog termination (i.e. a resistance at the end of a transmission line that prevents reflections of signals passing down the otherwise un-terminated transmission lines of the bus), 1B) pullups (so those transmission lines normally float at roughly 3V, unless actively driven by one of the boards plugged into the bus) and 1C) 'SACK turnaround' (a start-up 'safety check' where an un-requested - and thus 'un-grabbed' by any device - bus grant from the CPU on start-up is 'turned around' by the terminator; this verifies that the grant lines are un-broken between the CPU and the terminator - e.g. by someone forgetting to plug in a grant jumper). 1A is not _absolutely_ necessary; this can be seen in small QBUS systems (the QBUS is, at the analog level, sort of identical to the UNIBUS; this an be seen in the use of the same transceiver chips, such as 8641's, on both) which can get away without 1A in small configurations. Whether it's needed on your -11/24 is hard to predict, theoretically; the easiest thing is to just try it and see. Note: it may 'work' without it, but not be as _reliable_ as with it. 1B _is_ necessary, but can be provided anywhere on the bus; most UNIBUS/QBUS CPUs have it built in, and so does the KDF11-U of the -11/24: see pg. of MP01028. 1C is required by _some_ UNIBUS CPUs (ISTR that the -11/04 won't run without it), but the KDF11's in general don't; e.g. the -11/23 definitely runs without it. The KDF11-U might have outboard circuitry to require it, but I'm too lazy to grovel over the prints to see. Easiest to just try it and see. For 2, it all depends on what you're booting from. E.g. the RK11 has a simple enough bootstrap that you can just enter it manually (although it gets old after a while - I remember re-'programming' (think 'soldering iron' :-) a castoff BM-792 someone gave us for our -11/40 so I wouldn't have to). But if you're loading it over the console serial line, e.g. with PDP11GUI, you don't need any ROM bootstrap - the built in console ODT will be enough. You can also load a bootstrap that way; I was booting off the QSIC RK11 with a boostrap loaded over the console serial line; that was faster than the bootstrap in the BDV11. This requires finding - or writing - a bootstrap, which for later DEC mass storage controllers is not trivial. YMMV. TLDR version - probably not! Noel

3 years, 2 months

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KK11-A cache for -11/34A on eBait

by jnc＠mercury.lcs.mit.edu

Anyone want a KK11-A: https://www.ebay.com/itm/275173894774 US$200 sounds like a lot, I know, but KK11-A'S and FP11-A's are going for that much; an FP11-A just went for US$250. And KK11-A's are rare; this is he first one in a while. Noel

3 years, 2 months

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Is The M9312 Boot Module Essential?

by jnc＠mercury.lcs.mit.edu

> From: Rob Jarratt > I suspect some of the other cards that were in the machine might do the > necessary termination stuff. Different answers for each part of the functionality. 1A and 1C fundamentally have be at the end of the bus, physically. So, unlikely; since _other_ cards aren't, generally, designed to go there. 1B could be anywhere, but I've basically never seen anything but a CPU or a terminator with 1B functionality - probably in part because the same physical components uually do both 1A and 1B. (Oddball exception: M981 UNIBUS jumper, in the -11/40 - but that's 'sort of' part of the CPU.) 2, yes. E.g. the KT24 UNIBUS map has sockets to hold bootstrap PROMs. (Compatible with the M9312's.) Others, too; e.g. the KTJ11-B UNIBUS adapter (although that is not seen in an -11/24). Maybe others, but I can't recall off the top of my head. Noel

3 years, 2 months

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Testing H745 Regulators

by robert.jarratt＠ntlworld.com

I am trying to test a couple of H745 regulators with a DC bench PSU and I am having some problems with testing them. My bench PSU is a twin unit so I can supply the +15V required as well as the "AC" input using 20VDC from the other half of the bench PSU. The problem is that I don't think the bench PSU can supply enough startup current to allow the regulator to run. It can only supply 5A max. I have seen with the H744s that if I put too big a load on them, then they can't start because of the heavy startup current required. I can start them with a lower load and then add load once the regulator is running without breaching the current limit of the PSU. With the H745s I have tried reducing the load to see if I can get them to start, but a 10R load appears to be too much and the regulators draw the full 5A without outputting -15V. I have two H745s, both exhibit the same behaviour. I suppose they could both have the same fault, but I am inclined to think that perhaps they need a higher startup current than I can supply. Can anyone confirm this? Thanks Rob

3 years, 2 months

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ID these DEC floppy disks

by cz＠alembic.crystel.com

Hey all! While going through floppies I found these and was wondering what they were. Only clue in Google was someone asking in 1997 same thing. BL-T540B-M1 CZUFDB1 USER TESTS BL-T541B-M1 CZXD1B1 FIELD SERVICE TESTS 1 BL-T542B-MC CZXD2B0 FIELD SERVICE TESTS 2 BL-T565B-MC CZXD3B0 FIELD SERVICE TESTS 3 BL-T583B-MC CZXD4B0 FIELD SERVICE TESTS 4 Any ideas? The first one does not have a write protect tab, the others do. There is also one other disk I found CZMX4E0 Micro 11 Maint RX50 4 On this one the write protect flag was torn off (was on from factory and removed) C

3 years, 2 months

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HP 2100S Power Supply Disassembly Tips

by derschjo＠gmail.com

Hey all -- I've had this HP 2100S mini sitting on the bench for a bit, waiting, and I wanted to go through the power supply and test/reform the capacitors this past weekend. The processor service docs cover getting the supply out (which is slightly cumbersome) and I have that step done. But neither the processor docs nor the power supply service docs seem to cover how one disassembles the supply itself. (Has a really thorough guide to how the thing works though, that I'm hoping I won't actually have to use anytime soon.) There are a lot of parts in this unit, and I'm not seeing a method to the madness. The capacitors are fairly easy to *get to* but actually removing them for testing / replacement seems to be another matter entirely. Anyone out there done this before and have any advice? Thanks! - Josh

3 years, 2 months

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Red Hat Linux 7.2 for Alpha

by p.gebhardt＠ymail.com

Hi Ben, >? I can't seem to find this anymore.? I have seen a few mentions that there is a "wrapper" installer that is necessary to install 7.2 on an ES47/ES80 >machine, and I'm hoping that it was archived or mirrored some place... Back then in 2016, I also looked for these images for my ES80 machine on the HP site and tried to find ftp mirrors, but all I found were broken links. I would be happy, too, if anybody has a copy of these installation sets. Cheers, Pierre

3 years, 2 months

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VCF Swap Meet in Wall, NJ Sat, Feb 26 - Vintage Computers, Amateur Radio, TV, Radio, other Tech

by jeffrey＠vcfed.org

*The vintage Computer Federation will be having their 3rd swap meet.* *Saturday, February 26, 2022* *8AM to 2PM* *ADDRESS*: *Indoor swap Meet* InfoAge Science and History Museums (Camp Evans) 2201 Marconi Road, Wall, NJ 07719 Buildings 9010-D, 9032-A, 9001 *GPS location*: Google Maps <https://goo.gl/maps/YiEnhJAtffHTnfn8A> *Satellite Map*: *Street Map*: *EMAIL*: swapmeet at vcfed.org *PHONE*: 732-722-5015 *Flyer:* 2022-VCF-Swap-Meet-Flyer <https://vcfed.org/wp/wp-content/uploads/2022/02/VCF_Swap_Meet_2_26_2022_LQ_…> *Website*: https://vcfed.org/wp/vcf-swap-meet/ *VENDOR COST* is per space. First space is $20, each additional space is $10. This time it is an *indoor* swap meet. *Bring your own table!* Table isn?t required, but recommended. A space is considered a 6 by 3 foot area (the general size of a table). *Vendor setup at 7AM.* *FREE GENERAL ADMISSION!* *SEND PAYMENT TO*: paypal at vcfed.org (FRIENDS AND FAMILY OPTION) Write in the note section: [your name] VCF Swap Meet 2/26/2022 Number of spaces: *Click HERE for Swap Meet Vendor Signup* <https://docs.google.com/forms/d/e/1FAIpQLSfplnIROL-TTJ3qNkIo45mTelGNY3QCaFi…> * Reservation doesn?t guarantee sales. * The Vintage Computer Federation is only providing a space, vendors must bring their own tables. * In case of inclement weather, money paid will be refunded. * All items that you bring must be taken with you. No items are to be left behind. * Bathrooms on site * Limited food and drink options available. The same info can be found here: https://vcfed.org/wp/vcf-swap?meet <https://vcfed.org/wp/vcf-swap-meet> *EMAIL*: swapmeet at vcfed.org *AFTER THE SWAP MEET, COME VISIT OUR VCF MUSEUM @ INFOAGE!* We are open from 12PM to 5PM: https://vcfed.org/wp/vcf-museum The Vintage Computer Federation Museum is located nearby the swap meet and is part of InfoAge Science and History museums. InfoAge and VCF Museums are open every Saturday, Sunday and Wednesday from 12PM to 5PM InfoAge museums: infoage.org.

3 years, 2 months

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Red Hat Linux 7.2 for Alpha

by ben＠huntsmans.net

Hi guys- Is anyone aware of an archive or mirror of HP / Compaq's Red Hat Linux 7.2 for Alpha download site: ftp://ftp2.compaq.com/pub/linux/RedHat/7.2-alpha/release-isos/ And the update site: ftp://ftp2.compaq.com/pub/linux/RedHat/7.2-alpha/updates/ I can't seem to find this anymore. I have seen a few mentions that there is a "wrapper" installer that is necessary to install 7.2 on an ES47/ES80 machine, and I'm hoping that it was archived or mirrored some place... Thanks in advance! -Ben

3 years, 2 months

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DECTape head problem

by go＠aerodesic.com

In debugging my DECtape interface lashup, I found that one of my head has two open windings.? Specifically, one channel has an open 'ground' with the other two lines apparently the full winding of the channel.? The second channel failing has no continuity between any of the three lines.? I have tested the other head and it has all the requisite continuity so I'm hoping I can at least get a single spindle running. Visual inspection of the head 'suggests' it might be caused by the age-old 'wire stress' of being captured within a polyester resin and then finally snapping due to internal stress.? I see lots of internal stress cracks on this head so I'm probably toast on this one. Are there documents on how the heads are made?? I.e. number of turns of number X wire; cap of X micros etc.? I'm not (yet) seriously entertaining the idea of rebuilding this head, but it looks pretty low tech.? These heads are Western Magnetic heads without a model number (only serial number 19976 - don't know the other head S/N as I haven't removed it yet.) And the look to be hand made... Has any ever attempted repair of one of these? -Gary

3 years, 2 months

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Varian 620/L backplane netlist?

by mark.kahrs＠gmail.com

I realize this a rare bird indeed, but would anyone just happen to have a Varian 620/L backplane netlist hanging around? Unless I missed it, the schematics on bitsavers do *not* have it.

3 years, 2 months

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AlphaServer ES47 partitioning

by ben＠huntsmans.net

Hey guys- Anyone on here know much about the Marvel boxes? I've had one for years but never had much time to fiddle with it. I'm looking at the partitioning features. In particular, the manual says: Hard partitions must be on 2P boundaries Tru64 only supports hard partitions However, I can confirm that you can definitely create a hard partition with a single CPU. This got me thinking, and I dug a little deeper into the MBM CLI. The manual seems to suggest that this is the case, but says that the operating system won't work correctly in that configuration. Anyone know why not? When you create a hard partition, you specify what type of subpartition the hard partition can contain. The manual says that only "soft" partitions are officially supported, but the CLI also allows you to create subpartitions of type "firm" and "semi-firm". Does anyone know what "firm" and "semi-firm" partitions do differently than soft partitions? And does Tru64 work with any of that, or is all of that OpenVMS-specific stuff? Also, on a side note, I don't suppose anyone here has a rail kit for an ES47 or ES80 they'd like to sell, or an I/O drawer... Many thanks in advance! -Ben

3 years, 2 months

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More switchmode power supply grief - Cisco IGS router

by cctalk＠beyondthepale.ie

I have a Cisco IGS router which hasn't worked for a long time. When I was last using it several years ago, it occasionally crashed and restarted. This turned out to be due to a poor contact on a connection in the cable going from the output of the power supply to the main board. I cleaned the contact more than once but it was difficult to make it good enough to ensure reliability. When I switched it on more recently, it was completely dead, no LEDs, no fan noise, no anything. I put it in the naughty pile and it sat there for a few years before I got around to looking at it. Today I finally managed to check it out. The ceramic F4A mains input fuse beside the power switch on the back panel had blown. When I opened it up, I found a POWER-ONE MAP80-4000 power supply. The main chopper transistor labelled Q1 on the PCB is almost a dead short. It is a large plastic packaged FET mounted on a piece of aluminium which is in turn screwed to the case for heatsinking. Unfortunately, there are no markings on it so I have no idea what to replace it with :-( As Q1 is shorted across all three terminals, whatever drives it may be damaged too :-( After finding screw heads hidden under the label, I managed to extract the PCB from the case and found some corrosion underneath, possibly from leaking electrolytic capacitors :-( There are lots of data sheets available for this power supply on the web but they concentrate on the specifications for the unit and don't say anything about the components :-( There are also lots of people offering to sell power supplies like this for way more than I am interested in spending on this project :-( I could replace the power supply with a different one, however, I don't have anything to hand that will fit in the approx 5-6cm headroom :-( Anyone have any suggestions? Regards, Peter Coghlan.

3 years, 2 months

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WTB: DEC VSXXX-AA Mouse or Compatible

by lists＠glitchwrks.com

All, I'm looking for a DEC VSXXX-AA "hockey puck" mouse or compatible for a VAXstation 3100. Thanks, Jonathan

3 years, 2 months

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Vintage computers Swap-meets in Knoxville region

by peveep＠gmail.com

Between the 30th of March and the 20th of April. I am a computer collector from England and specialise on computer artefacts >from the 1940s to the 1970s. and would love to attend one of these when visiting my son in TN. Many thanks, peter vp

3 years, 2 months

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TTL substitute for DTL

by cclist＠sydex.com

I've got a piece of gear here with a bad MC858P used as a bus driver--terminated in 220/330 ohms at the far end. Given that old DTL is a hit-or-miss proposition, I'm proposing to substitute a 7438 OC buffer. Pinout's the same, as is Vcc. Before I get out the soldering iron, any "don't do it" thoughts? --Chuck

3 years, 2 months

2
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Wanted: Pinout IDT 49C402 PGA84

by holm＠freibergnet.de

Hi, I have 4 pcs. IDT49C402 Bit Slices, it is no problem to find a datasheet for that chip..but it is an problem to find the pinout for the PGA84 Package. In all Datasheets that I've found only DIP68, LCC/PLCC68 PGA68 and CERQUAD68 are listet.. Has anyone a databook newer than 1989 where the PGA84 Pinout is listed? TIA, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info at tsht.de Fax +49 37292 709779 Tel +49 37292 709778 Mobil: 0172 8790 741

3 years, 2 months

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PDP-11/34 CPU PROMS

by jnc＠mercury.lcs.mit.edu

> From: Warner Losh > Do those chips have ROM numbers on them? I have updated the: https://gunkies.org/wiki/KD11-E_CPU https://gunkies.org/wiki/KD11-EA_CPU articles with the DEC part numbers for the i) microcode and ii) instruction decode PROms. That's not all the PROMs on the Control card - there are effing bazillions of the damned things (I suspect they used them to reduce the amount of random logic, so the CPU'd fit on two boards) - but it's most of them. I have yet to triple-check them, so there might still be transcription error or two. > From: Rod Smallwood > I am sure somebody will come up with the actual images either the > original files or derived from what we have. I wouldn't be too sure of that; silence so far. I have reached out to Mike Douglas, to ask where the microcode dump on DeRamp came from: perhaps the originator can help with the missing bits. (Although perhaps I should ask Al K; BitSavers also has the dump, and it's older, so perhaps that copy came >from the originator.) > We have narrowed the problem down. > Its the instruction decode ROM's that are the issue. > The images of those are whats needed. All of them? Or is just one failed? I'm wondering if you've just had a single one lose a bit or two; that's somewhat common in old PROMs. The chip you reported as failing (E111) almost certainly couldn't have taken out an instruction decode PROM, it's nowhere near them. I ask because we have absolutely nothing on those PROM's contents. With the microcode PROMs, we at least have the contents in symbolic form (see pg. 15 of MP00082; alas, we don't seem to have the KD11-EA equivalent of Table 7-15 >from EK-FP11A-TM-002), but for all the instruction decode PROMs - nada. Absolutely nothing. But if they're _mostly_ there, with the partial contents, and a description of the failure mode (e.g. 'SETC doesn't set the C bit'), we might be able to work out what bit got dropped. Failing that, someone's going to have to volunteer to unsolder a set, and read them out - at least, I assume that's what would have to be done. Perhaps a logic analyzer could be attached to an instruction decode ROMwhile the CPU ran diagnostics, and eventually a complete readout of the contents accumulated. Noel

3 years, 2 months

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PDP-11/34 CPU PROMS

by jnc＠mercury.lcs.mit.edu

>>> On Tue, Feb 8, 2022 at 6:18 PM Rod Smallwood wrote: >>> On the M8266 CPU control board a defective 7404 (E111) has killed a >>> bunch of the PROMs holding the microcode. That's pretty astonishing; I've heard of PROMs dropping bits over time, but I'm a bit amazed to hear of a failure in a TTL gate (the 74S04 is a hex inverter; its gates are on pg. 7 of the M8266 prints - they produce uPC03-08) taking out a bunch of other gates connected to it. >> On Tue, Feb 8, 2022 at 7:04 PM Warner Losh <imp at bsdimp.com> wrote: >> I found >> https://deramp.com/downloads/mfe_archive/011-Digital%20Equipment%20Corporat… >> which has the source code... >> >> But I couldn't find the tools to use these files to create microcode >> images. Actually, the "m8266_ucode.v.txt" there seems to actually be the program that produced the symbolic dump (which is also available at: http://www.bitsavers.org/pdf/dec/pdp11/1134/m8266_ucode.out.txt) It looks like the program is in VHDL or something like that, but it doesn't seem to have the actual microcode (was it stored/defined in another VHDL file?); that raises the question of where the actual microcode that it was dumping was. It might be worth inquiring of Mike Douglas (he runs the DeRamp site) to find out where the files in "mfe_archive" came from; perhaps the source has, or knows of, the file which "m8266_ucode.out.txt" was a symbolic dump of - maybe >from a complete KD11-EA simulation in VHDL? If that's not possible,it would be trivial to extract the PROM contents (well, partial contents - see below) from the "m8266_ucode.out.txt" file; each uword entry starts with the lines: ***** PDP-11/34a micro code word for MPC = 000 ***** (MSB is left, indented fields generated by expansion ROMs) micro word........ = 0000 0111 1100 0000 1100 1000 1010 0001 0000 0000 1110 0000 from ROM: E105 E103 E104 E100 E98 E97 E99 E106 E107 E108 E109 E110 The address of each uword is the "MPC = xxx" line; the contents of the 12 PROMs, at that address, are given on the "micro word........ = " line (the PROMs are 4 bits wide). If someone explained what format they needed as input for burning new PROMs, I could easily (like an hour) write a small portable program (using StdIO only, so it could be compiled and run on _anything_) that read that file in, and spat out the 12 PROM files. (Most of the dump could be ignored - all the data that's needed is in that one line.) BUT (and this is why it would be good to get back to the source of that file), that's not a complete M8266 ucode PROM dump. The KD11-EA has a uword address space 1 bit larger than the KD11-E - almost certainly to support floating point instructions; the KD11-EA adds 'uPC 09' (although looking its source at the top of pg. 7 of the prints, I don't quite grok how it is generated - maybe it's fed back through J2 from the FP11-A when one is plugged in). Anyway, uword addresses run up to 02000 in the KD11-EA, and the last uword in that dump is 0777. Interestingly, according to the flow charts of the 'basic' KD11-E/EA ucode in the prints (indexed and annotated here: https://gunkies.org/wiki/KD11-E/EA_microcode in full), they stop at 0757 - but the dump (in "m8266_ucode.out.txt") contains uwords that are 'supposed' to be blank (per the flow charts), as well as above 0757. So that dump must have been prepared from a copy of the 'new' KD11-EA PROMs - the ones including the floating point ucode. (Note that the FP11-A _also_ contains ucode, intended to control the stuff on the FP11-A; but the floating point instructions _also_ use the KD11-A for some stuff - e.g. fetching operands from main memory. Only the ucode address space is shared.) > From: Warner Losh > There's a small chance that the tools.tar.gz link on > http://www.ak6dn.com/PDP-11/M9312/ has these, but that's for a > different module so who knows. Right, a _completely_ different card - a boot PROM, not a CPU; totally un-related - and by a different person (Don North). But just for completeness, I looked in "tools.tar.gz", and it's just bootstrap PROM stuff. Noel

3 years, 2 months

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Retro Chip Tester Pro, done!

by wh.sudbrink＠verizon.net

You may recall that, a few weeks ago, I requested parts help (shopping baskets) for the Retro Chip Tester Pro that I got for Christmas. Well, today's mail brought the last few parts and I have finished and tested it. Wow! The only thing that it doesn't do is slice bread. It's great. I've put up a few pictures here: http://wsudbrink.dyndns.org:8080/images/RCTPro/ I got the 4008 and 1702 adapters with it, but I'm pretty sure that I will get the rest over the next month or so. This is the latest HW version with the latest release software. Bill S. PS: Thanks to everyone that helped with parts. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

3 years, 2 months

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DECTape head problem

by amp1ron＠gmail.com

> So it sermsdectape heads are special. I don?t think Dec would have the desire to make them internally so they probably contractef with a company already set up to do that. Who were the big tape head manufacturers at that time? Does anyone know? A photo of the back of a TU56 DECtape head can be seen at https://www.pdp8online.com/tu56/pics/head_label.shtml?small . The head has a label on it that reads: Western Magnetics Glendale Calif. Record 7282 I've never seen a TU56 in person and have no idea if they have separate read, write, and erase heads or some other combo. The "Record" notation on the above head's label hints to me this might be a write head. I found that and other DECtape photos at https://www.pdp8online.com/tu56/tu56.shtml . -- Ron

3 years, 2 months

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DECTape head problem

by michael.99.thompson＠gmail.com

> > > Date: Tue, 8 Feb 2022 20:55:31 +0000 > From: Wayne S <Wayne.Sudol at hotmail.com> > Subject: Re: DECTape head problem > > So it serms dectape heads are special. I don?t think Dec would have the > desire to make them internally so they probably contractef with a company > already set up to do that. Who were the big tape head manufacturers at that > time? Does anyone know? > We have one from Applied Magnetics Corporation, maybe the one in Goleta, CA. -- Michael Thompson

3 years, 2 months

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DECTape head problem

by go＠ao-cs.com

On 2/8/22 14:14, Wayne S via cctech wrote: > Searched a lille bit for Western Magnetics. Here?s a site that has some surplus heads, even a western magnetics onebut probably not the correct one. There is a corporate charter record for Western Magnetics in Minnesota dated 1964. Maybe this is the same company. There?s also a tape head from Michigan Magnetics. Maybe a merged company? > > https://www.surplussales.com/Equipment/magnetic-tape.html > > > Sent from my iPhone > > On Feb 8, 2022, at 13:05, Ron Pool via cctech <cctech at classiccmp.org> wrote: > > ? > So it sermsdectape heads are special. I don?t think Dec would have the desire to make them internally so they probably contractef with a company already set up to do that. Who were the big tape head manufacturers at that time? Does anyone know? > > A photo of the back of a TU56 DECtape head can be seen at https://www.pdp8online.com/tu56/pics/head_label.shtml?small . > The head has a label on it that reads: > Western Magnetics > Glendale Calif. > Record > 7282 > > I've never seen a TU56 in person and have no idea if they have separate read, write, and erase heads or some other combo. The "Record" notation on the above head's label hints to me this might be a write head. > > I found that and other DECtape photos at https://www.pdp8online.com/tu56/tu56.shtml . > > -- Ron > > Thanks.? Hadn't seen the Minnesota information.? Found some references but not actual company info.? Did find a reference somewhere it Canada, but I couldn't tell if it was original or successor company.? At any rate, no web presence nor telephone numbers found (yet.) I've dealt with the SurplusSales (of Nebraska) many times.? His prices are usually pretty high (not obscene, but just not 'surplus' prices I'm used to.)? However, he is a first-rate dealer and when he says something is so, you can count on it.? Never had problem with anything I was willing to *PAY* for.? I scanned the list you provided and found only a few 'digital' devices, unfortunately.? I suspect from 7 and 9 track mag tape drives.? I will scan his site and send him a ping so he'll be on? the lookout. -Gary

3 years, 2 months

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PDP-11/34 CPU PROMS

by rodsmallwood52＠btinternet.com

Hi ???????? Jerry Walker and I have an 11/34 under restoration. We have run into a bit of a problem. On the M8266 CPU control board a defective 7404 (E111) has killed a bunch of the PROMs holding the microcode. Does anybody have or can get images of the PROMs on this board so replacement devices an be programmed. Rod

3 years, 2 months

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Need 8mm or DLT-II tape?

by van.snyder＠sbcglobal.net

I have many 8mm tapes. A few are new. First comers get new ones. I have a few 8mm cleaning cassettes I have about a dozen DLT-II tapes. I have a Quantum DLT-II drive with wide SCSI LVD/SE interface I have some Ultrium LTO fibre-channel SCSI drives that were removed >from a tape-mounting robot several years ago. I never used them in my computers. The mounting bracket for one was modified to have an internal power supply -- which might be inadequate. ?I have one LTO tape. I have a 5.25" floppy drive. Yours for the price of shipping, or local pickup OK. Van Snyder van.snyder at sbcglobal.net La Crescenta, CA

3 years, 2 months

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DECTape head problem

by paulkoning＠comcast.net

> On Feb 8, 2022, at 5:14 PM, Wayne S via cctech <cctech at classiccmp.org> wrote: > > Searched a lille bit for Western Magnetics. Here?s a site that has some surplus heads, even a western magnetics onebut probably not the correct one. There is a corporate charter record for Western Magnetics in Minnesota dated 1964. Maybe this is the same company. There?s also a tape head from Michigan Magnetics. Maybe a merged company? > > https://www.surplussales.com/Equipment/magnetic-tape.html Those all look like audio heads, nothing even vaguely resembling a DECtape head. paul

3 years, 2 months

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Anyone live in Minneapolis?

by jnc＠mercury.lcs.mit.edu

> From: Steve at oldcomputers.net > There are some vintage tablets in Minneapolis (Eden Prarire) that would > like, but the seller will not ship. > Any help? When dealing with eBaiters who can't/won't ship, I have had good luck with PakMail (http://www.pakmail.com/); for a usually reasonable fee, they will go pick something up, package it properly, and ship it. In my experience with them, the shipping cost may not have been the absolute lowest possible I could have secured had I been on the spot, looking around, but.. I wasn't on the spot, looking around. And they went to the person's house, picked the thing up, and shipped it. Noel

3 years, 2 months

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Anyone live in Minneapolis?

by steve＠oldcomputers.net

There are some vintage tablets in Minneapolis (Eden Prarire) that would like, but the seller will not ship. Any help? You will have to pay, pick up, and ship. I would do it for you! Thanks- Steve in CA

3 years, 2 months

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DECTape head problem

by paulkoning＠comcast.net

> On Feb 8, 2022, at 2:53 PM, Wayne S via cctech <cctech at classiccmp.org> wrote: > > Since so many audio tape players and computer magtape units were made it would stand to reason that there has to be a stash somewhere of tape heads and it?s just a matter of finding where they are. > Are there any part numbers on the dectape heads? The schematics are bound to show DEC part numbers, but how those translate into supplier part numbers is anyone's guess. Or perhaps they were made internaly by DEC? In any case, DECtape heads are unusual. Computer tapes are normally 1/2 inch wide (a few old tape drives had different widths, like the 14 track 1 inch CDC tape). But DECtape and LINCtape are 3/4 inches wide, with 10 head positions. Audio tapes are unlikely to be helpful; consumer reel to reel tape is 2 tracks (interleaved for when you flip over the reel?) 1/4 inch; professional decks might have 8 tracks or more on 1/2 or 1 or 2 inch wide tape, but I don't remember ever seeing 3/4 inch wide audio or instrumentation heads. paul

3 years, 2 months

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DECTape head problem

by go＠ao-cs.com

On 2/7/22 12:48, Marc Howard via cctech wrote: > The problem would be the non-standard track size and number of tracks. > However if at least one of the head's paired tracks is good you could > potentially cut the drive current in half and double the read amplitude and > just use one track for the affected channel. > > Marc > > On Mon, Feb 7, 2022 at 12:33 PM Wayne S via cctech <cctech at classiccmp.org> > wrote: > >> I?ve often wondered if the tape heads from consumer tape devices such as >> cassette or 4-8 track tape players could be used or be made to be used as >> replacements. Anybody ever try that? >> >> Sent from my iPhone >> >>> On Feb 7, 2022, at 11:51, Michael Thompson via cctech < >> cctech at classiccmp.org> wrote: Further, the DECTape had various track-to-track spacing.? Between the the Mark track and the first data track on both edges, the spacing is at a little less than twice that between the mark and timing tracks or between each set of data tracks.? Put a different way, the track spacing is: T.M..D.D.D.D.D.D..M.T The magnetic poles of each head is roughly 1mm wide with about .8 mm spacing heads? The '..' in the above means there is about 1.4mm spacing (between 'M and D' and 'D and M', for example - the measurements are crude, so I could be off 20% or more.) I've searched the documents I have (many from bitsavers) and haven't yet spied a specification for the head design.? I suppose if I could determine the head 'gap' and knowing the magnetic flux required of the tape (with proper margins) and knowing the stated impedance of the head and drive current, I could figure out how many turns of some size wire is required (looks to be at least as small as #40). Back when I was a bit younger and less experienced (and didn't know it was impossible,) I actually 'repaired' (for some definition of 'repair') an old 1/4 inch tape head.? But all I did was pull some wire off the coil and delicately soldered a tap to this wire.? It worked ok for a couple of years but was obviously failed again from rough handling.? Fortunately it was 'easy' since there wasn't a bunch of clear epoxy in the way ;-)? I'm not sure today I would have the temerity to even try. Hoping one will show up someday and I can make a deal as to complete my unit. Thanks to all who have replied. -Gary

3 years, 2 months

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DECTape head problem

by bitwiz＠12bitsbest.com

I wonder if there are any professional audio multi-track recorders that match the tape width, number of tracks and tack pitch and have the necessary frequency response. On 2/7/2022 3:05 PM, Marc Howard via cctech wrote: > 8 track tapes use 1/4" wide tape. Most 8 track units use heads with only > two tracks implemented. There was a stepper solenoid that moved the head > down (or up after all 4 stereo programs were played). Growing up in the > 60s you never forget things like listening to In-A-Gadda-Da_Vida fade in > the middle of the drum solo and a loud "klunk-klunk" sound and the song > resuming. > > Some true 8 track heads were made for mastering pre-recorded tapes and > maybe for consumer recorders. > > Marc > > > On Mon, Feb 7, 2022 at 12:51 PM Michael Thompson via cctech < > cctech at classiccmp.org> wrote: > >> DECtapes have 5x redundant tracks. If you could find an 8-track head that >> had the same track pitch, and maybe track width, you could read the tape >> but lose redundancy on the Mark and Timing tracks. That probably would not >> work with a marginal DECtape. >> >> On Mon, Feb 7, 2022 at 3:33 PM Wayne S <wayne.sudol at hotmail.com> wrote: >> >>> I?ve often wondered if the tape heads from consumer tape devices such as >>> cassette or 4-8 track tape players could be used or be made to be used as >>> replacements. Anybody ever try that? >>> >>> Sent from my iPhone >>> >>>> On Feb 7, 2022, at 11:51, Michael Thompson via cctech < >>> cctech at classiccmp.org> wrote: >>>> ? >>>>> >>>>> From: Gary Oliver <go at aerodesic.com> >>>>> Subject: DECTape head problem >>>>> >>>>> In debugging my DECtape interface lashup, I found that one of my head >>>>> has two open windings.? Specifically, one channel has an open 'ground' >>>>> with the other two lines apparently the full winding of the channel.? >>>>> The second channel failing has no continuity between any of the three >>>>> lines.? I have tested the other head and it has all the requisite >>>>> continuity so I'm hoping I can at least get a single spindle running. >>>>> >>>>> Has any ever attempted repair of one of these? >>>>> >>>>> -Gary >>>>> >>>> At the Rhode Island Computer Museum we found several DECtape heads on >>> TU55 >>>> and TU56 drives with open connections. A volunteer got one head X-Rayed >>> so >>>> we could see the solder joints between the tiny wires for the head >> coils, >>>> and the larger twinax wires that go to the relay board. We couldn't see >>> any >>>> damage to the wires or solder joints. >>>> >>>> We tried heating the potting material to soften it, and digging it out >> to >>>> get to the solder joints. While digging at the potting material you >> can't >>>> see the tiny wires, so they will likely get damaged. >>>> >>>> We considered using a solvent to remove the potting material, but >> thought >>>> that it would eat the enamel off the head coil wires and damage them >>> beyond >>>> repair. >>>> >>>> So far we haven't found a way to repair the heads. >>>> >>>> Michael Thompson >> >> -- >> Michael Thompson >>

3 years, 2 months

1
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DECTape head problem

by michael.99.thompson＠gmail.com

DECtapes have 5x redundant tracks. If you could find an 8-track head that had the same track pitch, and maybe track width, you could read the tape but lose redundancy on the Mark and Timing tracks. That probably would not work with a marginal DECtape. On Mon, Feb 7, 2022 at 3:33 PM Wayne S <wayne.sudol at hotmail.com> wrote: > I?ve often wondered if the tape heads from consumer tape devices such as > cassette or 4-8 track tape players could be used or be made to be used as > replacements. Anybody ever try that? > > Sent from my iPhone > > > On Feb 7, 2022, at 11:51, Michael Thompson via cctech < > cctech at classiccmp.org> wrote: > > > > ? > >> > >> > >> From: Gary Oliver <go at aerodesic.com> > >> Subject: DECTape head problem > >> > >> In debugging my DECtape interface lashup, I found that one of my head > >> has two open windings.? Specifically, one channel has an open 'ground' > >> with the other two lines apparently the full winding of the channel.? > >> The second channel failing has no continuity between any of the three > >> lines.? I have tested the other head and it has all the requisite > >> continuity so I'm hoping I can at least get a single spindle running. > >> > >> Has any ever attempted repair of one of these? > >> > >> -Gary > >> > > > > At the Rhode Island Computer Museum we found several DECtape heads on > TU55 > > and TU56 drives with open connections. A volunteer got one head X-Rayed > so > > we could see the solder joints between the tiny wires for the head coils, > > and the larger twinax wires that go to the relay board. We couldn't see > any > > damage to the wires or solder joints. > > > > We tried heating the potting material to soften it, and digging it out to > > get to the solder joints. While digging at the potting material you can't > > see the tiny wires, so they will likely get damaged. > > > > We considered using a solvent to remove the potting material, but thought > > that it would eat the enamel off the head coil wires and damage them > beyond > > repair. > > > > So far we haven't found a way to repair the heads. > > > > Michael Thompson > -- Michael Thompson

3 years, 2 months

1
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DECTape head problem

by michael.99.thompson＠gmail.com

> > From: Gary Oliver <go at aerodesic.com> > Subject: DECTape head problem > > In debugging my DECtape interface lashup, I found that one of my head > has two open windings.? Specifically, one channel has an open 'ground' > with the other two lines apparently the full winding of the channel.? > The second channel failing has no continuity between any of the three > lines.? I have tested the other head and it has all the requisite > continuity so I'm hoping I can at least get a single spindle running. > > Has any ever attempted repair of one of these? > > -Gary > At the Rhode Island Computer Museum we found several DECtape heads on TU55 and TU56 drives with open connections. A volunteer got one head X-Rayed so we could see the solder joints between the tiny wires for the head coils, and the larger twinax wires that go to the relay board. We couldn't see any damage to the wires or solder joints. We tried heating the potting material to soften it, and digging it out to get to the solder joints. While digging at the potting material you can't see the tiny wires, so they will likely get damaged. We considered using a solvent to remove the potting material, but thought that it would eat the enamel off the head coil wires and damage them beyond repair. So far we haven't found a way to repair the heads. Michael Thompson

3 years, 2 months

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KW11-L ON eBait

by jnc＠mercury.lcs.mit.edu

https://www.ebay.com/itm/393915648077 I've already got one for my machines that take one! Noel

3 years, 2 months

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Odd jumpers on a XT 2190 drive.

by g-wright＠att.net

I'm going through? a few of my ESDI? and MFM hard drives? and ran across?2 Maxtor? XT 2190 drives with? all of the Drive Id's (1-4) tie together with 1 long jumper and the drives have the write protect jumper is installed.? Not sure what theywould have been used for ??? Both are the same. Jerry

3 years, 2 months

2
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IBM 129 keypunch on Ebay

by ccth6600＠gmail.com

There is a nice looking IBM 129 keypunch on Ebay for what I think is a very reasonable "buy it now" price of US$1799: https://www.ebay.com/itm/333898748391 Shipping to Australia would be horrendous otherwise I would have bought it. Best regards Tom Hunter

3 years, 2 months

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Odd board in a pdp8/e

by cz＠alembic.crystel.com

I'm putting stuff together here and it's time to begin working on the 8/E. Looks like a pretty generic system but it has two odd boards. Pair of g227 memory boards, 4 board CPU+Console board, serial board, nothing too special. But two odd Omnibus cards: One is a memory board, half populated, my guess is it's enough memory to bring the computer to 32kw. The other is an mets 303-0115-001. Bunch of 7400 series logic chips, nothing too special. Any idea what it might have been? Timeshare option? Something else? Not a peripheral controller from what I can see. C

3 years, 3 months

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cctalk Digest, Vol 89, Issue 3

by bobsmithofd＠gmail.com

On Thu, Feb 3, 2022 at 1:08 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. (John Ames) > 2. Re: (Paul Koning) > 3. Re: (Jon Elson) > 4. Re: KMC11/DMC11 folllow up (Dave Mitton) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 2 Feb 2022 10:20:25 -0800 > From: John Ames <commodorejohn at gmail.com> > To: cclist at sydex.com > Cc: cctalk at classiccmp.org > Message-ID: > <CABCBCvP8SX_1rB3FXVxZuXx1SUFTfiJBTqePd_SZiNeReX7PEw at mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > > Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) > I think "witch settings" is my new preferred term for this. They're > certainly mysterious and arcane enough. > > > ------------------------------ > > Message: 2 > Date: Wed, 2 Feb 2022 13:30:33 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: John Ames <commodorejohn at gmail.com>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: > Message-ID: <B8F20F9C-A329-4CED-9A00-036EAA8F4D1A at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Feb 2, 2022, at 1:20 PM, John Ames via cctalk <cctalk at classiccmp.org> wrote: > > > >> Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) > > I think "witch settings" is my new preferred term for this. They're > > certainly mysterious and arcane enough. > > Nice. It would be a good term to apply to VMS SYSGEN parameters that are documented as having units "microfortnights". > > paul > > > > ------------------------------ > > Message: 3 > Date: Wed, 2 Feb 2022 16:49:42 -0600 > From: Jon Elson <elson at pico-systems.com> > To: Paul Koning via cctalk <cctalk at classiccmp.org> > Subject: Re: > Message-ID: <b0989916-7493-481d-7c45-a696ce5ecc31 at pico-systems.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > On 2/2/22 12:30, Paul Koning via cctalk wrote: > > > >> > > Nice. It would be a good term to apply to VMS SYSGEN parameters that are documented as having units "microfortnights". > > > A footnote in the system config guide noted that ufortnights > would be approximated at one second. > > Jon > > > > ------------------------------ > > Message: 4 > Date: Wed, 2 Feb 2022 14:31:27 -0500 > From: Dave Mitton <dave at mitton.com> > To: "cctech at classiccmp.org" <cctech at classiccmp.org> > Subject: Re: KMC11/DMC11 folllow up > Message-ID: <20220202193130.24EDC4E775 at mx2.ezwind.net> > Content-Type: text/plain; charset="utf-8" > > Date: Tue, 1 Feb 2022 18:46:46 -0500 > From: Bob Smith <bobsmithofd at gmail.com> > Subject: Re: KMC11/DMC11 folllow up > Message-ID: > I?ve been watching this thread go by, and never finding time to contribute?. > > I started in Aug 1977 and finished the CommIOP products from Bob and Harvey. Clarise was no longer involved. > It was basically done, I just did the QA on them and released it. I did find some bugs in the debugger we provided. > > I basically did KMC software support, on and off, going forward. When the KMC-B came out (I think Remi did that) > I rev?ed the tools. I also did a KMC Tools package for VMS. I tossed into that package a VMS line printer driver, I wrote as an example and POC, that ran multiples LP11s at significantly better speed. We ran that in our lab. The MIT LCS lab loved that. > > My memory is weak on things like the ?DMX? and other things that CSS did. The Lab Products group built some successful data collection products around the KMC. > > Attempts in the Comms HW group to do an updated UNIBUS DH never got off the ground. We (NAC) did pitch the idea of using the CommIOP-DZ to VMS, as a way to off-load character terminal loads, and they would have nothing to do with it. For whatever reasons, they did not like the idea of smart devices. > > That led to the attempt to build a ?universal? terminal concentrator based on an 11 networked into the system. That project was complicated by what it tried to integrate, and took too long to build. It was overtaken by the simpler LAT based products that DEC went forward with. > > George Conant, Bob Rosenbaum, and Pete Nesbeda left the company and founded Xyplex that fielded successful products in this space. > > I could go on, but ? I do have copies of the KMC Tools doc and maybe the CommIOPs, but no KMC hw docs. > Dave. > > Sent from Mail for Windows > > Hey Dave! I did not mention you because I was not sure you wanted to recall those days! you are correct it was Remi Lisee doing the design, I did the first line units, and then they were redone a few years later. Glad you piped in!! Hope you are doing great! All of you guys were brilliant, except Harvey, he was a royal pain, said with lots of laughs we both got tired or burning roms!! bob smith

3 years, 3 months

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No subject

by commodorejohn＠gmail.com

> Back in the bad old days of the 5160 PC, some DTC controllers allowed for partitioning a drive (using witch settings) I think "witch settings" is my new preferred term for this. They're certainly mysterious and arcane enough.

3 years, 3 months

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KMC11/DMC11 folllow up

by dave＠mitton.com

Date: Tue, 1 Feb 2022 18:46:46 -0500 From: Bob Smith <bobsmithofd at gmail.com> Subject: Re: KMC11/DMC11 folllow up Message-ID: <CAHtNYbXBRwrOQm2cH+T+CDn5nq3sZN+PQRa9fEMVhqQ=pAMDSw at mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Yes! thank you! Nice, smart, and did good work despite the magateer, I mean marketing dweeb. I lost track of Harvey, Bob wen ont to start a company over in west concord, can't recall the name, used some of his gear for projects in the mid 80s. I was designing a comms system in late 80s and heard Len Bosak had started a company, had a couple of meetings with him, and went with hs gear. Man those were fun post DEC projexcts. bob smith (PDP8 engineering, DecComm (Stockebrand, VInce et al), small systems, then of toe LCG for 2080... On Tue, Feb 1, 2022 at 2:43 PM John Forecast <john at forecast.name> wrote: > > On Feb 1, 2022, at 8:20 AM, Bob Smith via cctalk <cctalk at classiccmp.org> wrote: > > > > KMC11 - Paul K cited the docs. It was a bit different from DMC CPU board > > in both cycle time and in the use of ram versus prom. > > Both boards/products used the 4bit Alu but I don't call that bit > > slice, as the 2901 is more of a bit slice. > > KMC and DMC are Harvard architecture based devices, as is the 11/60 CPU. > > DMC and KMC benefited from the microcode work of Harvey Schlesinger, > > Bob Rosenbaum, Richie Larry, and I think Clarise joined the team in > > 77. Can't recall her last name. > > Patton? Harvey, Bob and Clarise joined the DECnet-RSX development team sometime in 77/78. > > John. > > > DMC had (when I left the project and it had been shipping for a year > > or two) a 300NS cycle time, while the KMC had a 240NS cycle time > > thanks to the instruction register I had suggested to remi as we were > > thinking of a RAM based device because PROMS were a royal pain with 2 > > and 3 code changes a day. This change allowed the machine to begin to > > access the next instruction as one was executing - there are no > > interrupts in either board. > > bob > I?ve been watching this thread go by, and never finding time to contribute?. I started in Aug 1977 and finished the CommIOP products from Bob and Harvey. Clarise was no longer involved. It was basically done, I just did the QA on them and released it. I did find some bugs in the debugger we provided. I basically did KMC software support, on and off, going forward. When the KMC-B came out (I think Remi did that) I rev?ed the tools. I also did a KMC Tools package for VMS. I tossed into that package a VMS line printer driver, I wrote as an example and POC, that ran multiples LP11s at significantly better speed. We ran that in our lab. The MIT LCS lab loved that. My memory is weak on things like the ?DMX? and other things that CSS did. The Lab Products group built some successful data collection products around the KMC. Attempts in the Comms HW group to do an updated UNIBUS DH never got off the ground. We (NAC) did pitch the idea of using the CommIOP-DZ to VMS, as a way to off-load character terminal loads, and they would have nothing to do with it. For whatever reasons, they did not like the idea of smart devices. That led to the attempt to build a ?universal? terminal concentrator based on an 11 networked into the system. That project was complicated by what it tried to integrate, and took too long to build. It was overtaken by the simpler LAT based products that DEC went forward with. George Conant, Bob Rosenbaum, and Pete Nesbeda left the company and founded Xyplex that fielded successful products in this space. I could go on, but ? I do have copies of the KMC Tools doc and maybe the CommIOPs, but no KMC hw docs. Dave. Sent from Mail for Windows

3 years, 3 months

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Origin of "partition" in storage devices

by tom94022＠comcast.net

There is a discussion of the origin of the term "partition" in storage devices such as HDDs at: https://en.wikipedia.org/wiki/Talk:Disk_partitioning#Where_did_the_term_%22p artition%22_originate? It seems clear it was used in memory well before HDDs but when it got started there is unclear. * IBM PC DOS v2 was an early user in 1983 with FDISK and its first PC support of HDDs * UNIX, Apple OS's and IBM mainframe all seem to come later. Partitioning as a "slice" probably predates IBM PC DOS v2 Would appreciate some recollections about DEC usage, other minicomputers and the BUNCH. You can either post directly to Wikipedia or let me know; links to references would greatly be appreciated Tom

3 years, 3 months

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Origin of "partition" in storage devices

by jnc＠mercury.lcs.mit.edu

> From: Tom Gardner > You define logical disks by assigning a logical disk unit number to a > file on a physical disk. You can then use the logical disk as though it > were a physical disk. To me, 'partition' implies a contiguous are of the disk; "a file" to me implies that it might not be contiguous? Or are files contiguous in the RT-11 filesystem? (I know there were filesystems which supported contiguous files.) This reminds me of the swapping/paging area in Windows 95/98 (maybe other versions too), which was kept in a file, and therefore might be scattered all over the physical disk. (Norton disk optimizer would coalesce the swap/paging area to a contiguous area of the disk.) Noel

3 years, 3 months

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KMC11/DMC11 folllow up

by bobsmithofd＠gmail.com

KMC11 - Paul K cited the docs. It was a bit different from DMC CPU board in both cycle time and in the use of ram versus prom. Both boards/products used the 4bit Alu but I don't call that bit slice, as the 2901 is more of a bit slice. KMC and DMC are Harvard architecture based devices, as is the 11/60 CPU. DMC and KMC benefited from the microcode work of Harvey Schlesinger, Bob Rosenbaum, Richie Larry, and I think Clarise joined the team in 77. Can't recall her last name. DMC had (when I left the project and it had been shipping for a year or two) a 300NS cycle time, while the KMC had a 240NS cycle time thanks to the instruction register I had suggested to remi as we were thinking of a RAM based device because PROMS were a royal pain with 2 and 3 code changes a day. This change allowed the machine to begin to access the next instruction as one was executing - there are no interrupts in either board. bob

3 years, 3 months

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Origin of "partition" in storage devices

by jnc＠mercury.lcs.mit.edu

> From: Paul Koning > When did Unix first get partitions? 'Partitions' the mechanism, or partitions the term for the mechanism? The former appeared about V5: https://minnie.tuhs.org/cgi-bin/utree.pl?file=V5/usr/sys/dmr/rp.c when an RP03 was added; pre-V7, UNIX filesystems were limited to 2^16 blocks, so the 406*10*20 blocks of an RP03 had to be split up into partitions (called 'sections' or 'pseudo-disks' in the documentation) to make all of it useable. The latter? No idea... Partitions may have appeared in DOS/Windows for much the same reason; with 32 KB clusters, FAT16 filesystems were limited to 2GB. I distinctly recall having to use partitions when I bought a 13GB hard drive for my Windows 95 machine (FAT32 only came in with Windows 95 OSR2). Noel

3 years, 3 months

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Origin of "partition" in storage devices

by tom94022＠comcast.net

A somewhat broader search found the 1984 RT-11 System Release Notes with the following: 1.4.2.4 Logical Disk Subsetting Handler (LD) - The logical disk subsetting handler lets you define logical disks, which are subsets of physical disks. You define logical disks by assigning a logical disk unit number to a file on a physical disk. You can then use the logical disk as though it were a physical disk. AA-5286F-TC-T1_RT-11_System_Release_Notes_Jul84.pdf (bitsavers.org) <http://www.bitsavers.org/pdf/dec/pdp11/rt11/v5.1_Jul84/AA-5286F-TC-T1_RT-11…> p15/102 Suggests DEC had not yet adopted the term ?partition? for a segment of a disk Tom -----Original Message----- From: Tom Gardner [mailto:tom94022 at comcast.net] FWIW a Google search: "partition site:http://www.bitsavers.org/pdf/dec/pdp11/rt11" returns no relevant hits prior to 1983 I suspect that ESDI and MFM controllers emulating RL/RK disks are also later than 1983 Tom -----Original Message----- From: Zane Healy [ <mailto:healyzh at avanthar.com> mailto:healyzh at avanthar.com] Sent: Monday, January 31, 2022 12:40 PM To: Paul Koning; General Discussion: On-Topic and Off-Topic Posts Cc: <mailto:t.gardner at computer.org> t.gardner at computer.org; Tom Gardner Subject: Re: Origin of "partition" in storage devices On Jan 31, 2022, at 11:28 AM, Paul Koning via cctalk < <mailto:cctalk at classiccmp.org> cctalk at classiccmp.org> wrote: > > Both of these are memory partitions. The only OS I can think of predating the ones you mentioned is RT-11, the later versions (V2 did not have them). When did Unix first get partitions? > > paul Partitions are pretty important in RT-11 v5.x, after all, there is the partition size limit, so you have to have multiple partitions for almost any HD, except very small ones. Let?s not forget hardware enforced partitioning, the WEQSD/04 ESDI controller comes to mind. It see?s a single large ESDI HD as a single disk, but you can partition it on the controller, and the OS sees each partition as a separate physical disk. I seem to remember some MFM controllers that made the MFM drive appear to be RL01/RL02 or RK05 packs. Zane

3 years, 3 months

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Pdp 8 panel parts for trade

by tdk.knight＠gmail.com

Anyone got any 8i switch or panel parts they Wana trade for any of these? Got 6 3 pin spring loaded rockers appear to test good might need some deoxot not sure came off the 8e below 8 of the 8e m rocker paddles orange and redish orange https://drive.google.com/file/d/1Eprlv8d3TmSPFJ3rCHIJTFkQOyAZesCM/view?usp=… Some are missing the plastic pivot dimples 8m with out it's switches The rotory it's bit weird but possibly usable. Dunno enough about them. It's center hole is ovaled a bit might gotten bashed. Might have some usefull bits still https://drive.google.com/drive/folders/1EpAag1J5r6RAR8ln_fprrdCEiOnJx5kq I've got some other bits that might be usefull as well from the 8i to anyone I'm looking for 5 more rockers with or with out the 8i paddles Or some 8i paddles I've got 5 brown and 10 white ones that I wanted to find when I rescued my poor 8i outs the mud Or any other parts that might be usefull

3 years, 3 months

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Bob Smith > the original UART was designed by DEC, Vince Bastiani was the project > lead and designer, Gordon Bell was behind the project, and it may have > been his idea. "Computer Engineering: A DEC View of Hardware Systems Design" covers this, in a footnote on pg. 73. I seem to recall reading that Ken Olsen was involved in doing early modem work (presumably on Whirlwind), but maybe my memory is failing, and it was someone else (like Bell, or someone). Too busy to research it at the moment... Noel

3 years, 3 months

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MG10 parts

by useddec＠gmail.com

While moving some things around I found the following: 7 M8588 6 M8591 6 M8592 4 M8593 14 M8594 All appear to be NOS. I also found : G103 G222 G223 M911 Which I did not count, and they seem to be memory related, but I haven't checked to see which memory they are from. If you have any interest please contact me off list. Thanks, Paul

3 years, 3 months

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > Maybe that is the dhv11. The DH11, DHV11 and DHU11 are all very similar, although not 100.00% program compatible. (The DHQ11 can be set to exactly emulate either the DHV11 or DHU11.) So, all provide DMA output, but not DMA input. Differences with the DH11 include two full word registers for DMA address, hardware ^S/^Q support, built-in diagnostics, etc. The DHV11 and DHU11 differ in hardware echo, output FIFO, a fix for the infamous DH11 input silo level bug, etc. Noel

3 years, 3 months

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ISO: Canon Scanner Driver

by silent700＠gmail.com

In order to further the effort of scanning and preserving ALL of the things, I picked up a Canon Microfilm Scanner 300 for $cheap. It has a SCSI interface and doesn't work with anything past Windows XP, but that's not a problem. What is a problem is that Canon's link to the XP driver is a big 4 0 4: https://www.usa.canon.com/internet/portal/us/home/support/details/scanners/… By any chance, does someone out there have this driver? The filename in question is "300350DRIT_V11.exe". You can google that name and end up either back at Canon's site or in Malware Hell ("just download this Chrome plugin to get your driver!"). Note that this is not the Canon Microfilm Scanner 300-II, which is a USB device and uses a different driver. Thanks for any leads... jt

3 years, 3 months

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cctalk Digest, Vol 88, Issue 30

by bobsmithofd＠gmail.com

IIRC, John Mac was the designer for the DHQ/DHV. If my memory is correct, after DH was done, John had the idea of a mix and match synchronous/Async mux and came up with those designs. I dont remember who was on his team. COMMS 11 group had led (farmed out) the designs of the Sync version of a UART called USynRT in some parlance SIg 2652 and SMC 5027 IIFC. I ran the Signetics contract tech side. A fresh MIT PhD was the Sig POC, and there are more stories about that. I cant recall his name at this juncture. bob On Sun, Jan 30, 2022 at 1:00 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. Re: What was a Terminal Concentration Device in DEC's > products? (Noel Chiappa) > 2. Re: What was a Terminal Concentration Device in DEC's > products? (Paul Koning) > 3. Re: What was a Terminal Concentration Device in DEC's > products? (Chris Zach) > 4. Re: What was a Terminal Concentration Device in DEC's > products? (Glen Slick) > 5. Re: What was a Terminal Concentration Device in DEC's > products? (Noel Chiappa) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 29 Jan 2022 15:58:53 -0500 (EST) > From: jnc at mercury.lcs.mit.edu (Noel Chiappa) > To: cctalk at classiccmp.org > Cc: jnc at mercury.lcs.mit.edu > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <20220129205853.15EEA18C07B at mercury.lcs.mit.edu> > > > From: Paul Koning > > > DH-11 is unusual in that it has DMA in both directions > > McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > Noel > > PS: I am familiar with the term 'terminal concentrator' from the networking > world, but as a generic term, not the name of a particular product. (Although > Cisco's first boxes may have included a terminal concentrator, so named.) > > Noel > > > > ------------------------------ > > Message: 2 > Date: Sat, 29 Jan 2022 17:12:41 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: Noel Chiappa <jnc at mercury.lcs.mit.edu>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <684F1FCF-A6E6-4F3C-AC39-ADA1504FC9E1 at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > > > >> From: Paul Koning > > > >> DH-11 is unusual in that it has DMA in both directions > > > > McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > > > http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > > > it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > paul > > > > ------------------------------ > > Message: 3 > Date: Sat, 29 Jan 2022 18:49:06 -0500 > From: Chris Zach <cz at alembic.crystel.com> > To: Paul Koning <paulkoning at comcast.net>, "General Discussion: > On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>, Paul Koning via > cctalk <cctalk at classiccmp.org>, Noel Chiappa > <jnc at mercury.lcs.mit.edu>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <24F062E4-8B26-4EB3-A573-B47C69A53B67 at alembic.crystel.com> > Content-Type: text/plain; charset=utf-8 > > Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow > > On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at classiccmp.org> wrote: > > > > > >> On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > >> > >>> From: Paul Koning > >> > >>> DH-11 is unusual in that it has DMA in both directions > >> > >> McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > >> > >> http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > >> > >> it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > > >Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > > > paul > > > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > > ------------------------------ > > Message: 4 > Date: Sat, 29 Jan 2022 16:47:27 -0800 > From: Glen Slick <glen.slick at gmail.com> > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: > <CAM2UOwL2hi2Crm7ovphGd+UZFPePV+vUzoduan7a2a5Xo+eimw at mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > http://www.bitsavers.org/pdf/dec/qbus/EK-DHQ11-UG-002.pdf > DHQ11 User Guide, EK-DHQ11-UG.002 > > The main application of the M3107 DHQ11 is for interactive terminal > handling; it can also be used for data concentration and real-time > processing. It has two programming modes, DHV11 and DHU11. The > register sets in these modes are compatible with those of the DHV11 > and DHU11 respectively. The preferred mode of operation is DHU11 mode. > The main features of the DHQ11 are: > > ? For transmission: DMA transfers; or for each line, program transfers > to a 1 character transmit buffer in DHV11 mode, or to a 64-character > transmit FIFO in DHU11 mode > > ? For receive: a 256-entry FIFO buffer for received characters, > dataset status changes, and diagnostic information > > The M3118 CXA16 and the M3119 CXA08 have the same programming > interface as the M3107 DHQ11 > > > The M3108 DSV11 can do DMA transfers in both directions, although it > is a synchronous interface, not asynchronous. > > http://www.bitsavers.org/pdf/dec/qbus/EK-DSV11-TM-001_Jan87.pdf > DSV11 Technical Manual, EK-DSV11-TM-001 > > Functional Description (Section 1.5). The DSV11 supports a range of > synchronous protocols on the serial interface, and transfers data to > and from the host by DMA transfer. This section describes the way in > which the DSV11 handles data. > > On Sat, Jan 29, 2022 at 3:49 PM Chris Zach via cctalk > <cctalk at classiccmp.org> wrote: > > > > Maybe that is the dhv11. Or the dv11 I'll look it up tomorrow > > > > On January 29, 2022 5:12:41 PM EST, Paul Koning via cctalk <cctalk at classiccmp.org> wrote: > > > > > > > > >> On Jan 29, 2022, at 3:58 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote: > > >> > > >>> From: Paul Koning > > >> > > >>> DH-11 is unusual in that it has DMA in both directions > > >> > > >> McNamara's DH11? (I don't know of another DECdevice of that name.) Per: > > >> > > >> http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… > > >> > > >> it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. > > > > > >Oh. That's amazing, all these years I thought it had DMA both ways. Clearly not. I wonder how I got that misunderstanding. > > > > > > paul > > > ------------------------------ > > Message: 5 > Date: Sun, 30 Jan 2022 09:26:46 -0500 (EST) > From: jnc at mercury.lcs.mit.edu (Noel Chiappa) > To: cctalk at classiccmp.org > Cc: jnc at mercury.lcs.mit.edu > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <20220130142646.5614818C074 at mercury.lcs.mit.edu> > > > From: Chris Zach > > > Maybe that is the dhv11. > > The DH11, DHV11 and DHU11 are all very similar, although not 100.00% program compatible. > (The DHQ11 can be set to exactly emulate either the DHV11 or DHU11.) So, all provide > DMA output, but not DMA input. > > Differences with the DH11 include two full word registers for DMA address, > hardware ^S/^Q support, built-in diagnostics, etc. The DHV11 and DHU11 differ > in hardware echo, output FIFO, a fix for the infamous DH11 input silo level > bug, etc. > > Noel > > > End of cctalk Digest, Vol 88, Issue 30 > **************************************

3 years, 3 months

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cctalk Digest, Vol 88, Issue 29

by bobsmithofd＠gmail.com

Back in 75-77 time frame, the KMC11 was packaged with DD11 backplane, a controller interface board or an SLU to implement version 2 of the DoD AUTODIN II. Philco Ford element then called Aeronuetronic Ford out ot Cali was the prime. DEC won the hardware portion bidding PDP11 systems using the KMC11 and SLUs ranging from Mode1 to Mode VI. I did the SLUs for Mode VI (ADCCP/SDLC et al) and Mode II (BiSync) out of the Comms 11 group. CSS Nashua did the Async system with I think 64 lines, or more, and labeled it DMX IIRC - my memory could be bad on the name.The COMM IOP concept was another alternative using the DZ/DU boards. Barney Loiter, if he is still around can probably remember who in CSS did the product. I think Frank Zareski, who had moved from Comms group to Semiconductor was involved with or the lead for the DUAL UART chips DEC invented (point for the record, the original UART was designed by DEC, Vince Bastiani was the project lead and designer, Gordon Bell was behind the project, and it may have been his idea.) On Sat, Jan 29, 2022 at 1:00 PM <cctalk-request at classiccmp.org> wrote: > > Send cctalk mailing list submissions to > cctalk at classiccmp.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.classiccmp.org/mailman/listinfo/cctalk > or, via email, send a message with subject or body 'help' to > cctalk-request at classiccmp.org > > You can reach the person managing the list at > cctalk-owner at classiccmp.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of cctalk digest..." > > > Today's Topics: > > 1. Re: simulation of an entire IBM S/360 Model 50 mainframe > (Curious Marc) > 2. What was a Terminal Concentration Device in DEC's products? > (Chris Zach) > 3. Re: What was a Terminal Concentration Device in DEC's > products? (Paul Koning) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 28 Jan 2022 20:53:22 -0800 > From: Curious Marc <curiousmarc3 at gmail.com> > To: Liam Proven <lproven at gmail.com>, "General Discussion: On-Topic and > Off-Topic Posts" <cctalk at classiccmp.org> > Subject: Re: simulation of an entire IBM S/360 Model 50 mainframe > Message-ID: <E6C6C3FB-E0A0-4472-A485-3EA9E1102CEC at gmail.com> > Content-Type: text/plain; charset=utf-8 > > Ah, it was you Liam. Ken is enamored with the new title you bestowed on him. He will now be officially called: Master Ken, Hardware Boffin. > :-) > Marc > > > On Jan 27, 2022, at 11:54 AM, Liam Proven via cctalk <cctalk at classiccmp.org> wrote: > > > > ?On Thu, 27 Jan 2022 at 17:20, Guy N. via cctalk <cctalk at classiccmp.org> wrote: > >> > >> This might be old news to a lot of people here, but I noticed a fun > >> article on The Register today: > > > > Oh cool. Thanks for the link -- that's one of my stories. Glad to hear > > people enjoyed it. :-) > > > > -- > > Liam Proven ~ Profile: https://about.me/liamproven > > Email: lproven at cix.co.uk ~ gMail/gTalk/FB: lproven at gmail.com > > Twitter/LinkedIn: lproven ~ Skype: liamproven > > UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 > > > ------------------------------ > > Message: 2 > Date: Sat, 29 Jan 2022 00:28:30 -0500 > From: Chris Zach <cz at alembic.crystel.com> > To: CCTalk mailing list <cctalk at classiccmp.org> > Subject: What was a Terminal Concentration Device in DEC's products? > Message-ID: <ba6ec80e-e099-4015-9d58-f33fb4e51c02 at alembic.crystel.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > Old question: I'm looking through some old reports from 1977 about a > failed DEC project with the DMX11 multiplexer system and there is > reference to the following key items: > > 1) The DMX was designed to handle block mode devices. Fine. > 2) Character mode devices like the VT52's were supposed to use a "TCD" > product from DEC. > > The reason the project imploded was because apparently DEC stopped > supporting the TCD in RSX11/D in late 1976, so someone in CSS had the > great idea of agreeing to extend the microcode in the DMX11 to handle > both block AND character mode devices. This did.... not work well and it > sank the project. > > What I'm wondering is what was the TCD for PDP11's back then? I don't > see anything in my communications handbooks on this, and even the DMX11 > doesn't really appear, instead there is the COMM/IO/P type boards which > worked with a pile of DZ11's. From what I can glean from this > documentation it looks like the DMX11 worked in a similar fashion as the > requirement was the DMX11 system was a nine board solution (possibly 8 > DZ11's and one controller board). > > More odd it looks like the TCD *was* still supported in RSX11/M and > ultimately the decision was made to build the thing in M so it's weird > they continued to whack away at the DMX solution instead of going with > TCD's for async and proven DMX microcode for block devices. > > Any thoughts, or does this jog any memories? > > C > > > ------------------------------ > > Message: 3 > Date: Sat, 29 Jan 2022 10:24:56 -0500 > From: Paul Koning <paulkoning at comcast.net> > To: Chris Zach <cz at alembic.crystel.com>, "cctalk at classiccmp.org" > <cctalk at classiccmp.org> > Subject: Re: What was a Terminal Concentration Device in DEC's > products? > Message-ID: <7F4B4A3F-4114-4FF9-9D6C-28AA7E26E475 at comcast.net> > Content-Type: text/plain; charset=us-ascii > > > > > On Jan 29, 2022, at 12:28 AM, Chris Zach via cctalk <cctalk at classiccmp.org> wrote: > > > > Old question: I'm looking through some old reports from 1977 about a failed DEC project with the DMX11 multiplexer system and there is reference to the following key items: > > > > 1) The DMX was designed to handle block mode devices. Fine. > > 2) Character mode devices like the VT52's were supposed to use a "TCD" product from DEC. > > > > The reason the project imploded was because apparently DEC stopped supporting the TCD in RSX11/D in late 1976, so someone in CSS had the great idea of agreeing to extend the microcode in the DMX11 to handle both block AND character mode devices. This did.... not work well and it sank the project. > > > > What I'm wondering is what was the TCD for PDP11's back then? I don't see anything in my communications handbooks on this, and even the DMX11 doesn't really appear, instead there is the COMM/IO/P type boards which worked with a pile of DZ11's. From what I can glean from this documentation it looks like the DMX11 worked in a similar fashion as the requirement was the DMX11 system was a nine board solution (possibly 8 DZ11's and one controller board). > > > > More odd it looks like the TCD *was* still supported in RSX11/M and ultimately the decision was made to build the thing in M so it's weird they continued to whack away at the DMX solution instead of going with TCD's for async and proven DMX microcode for block devices. > > > > Any thoughts, or does this jog any memories? > > Nothing comes to mind here; the name "DMX" does not ring any bells. It's a bit before my time, admittedly. > > DEC made some products that used block mode terminals: the moderately successful Typeset-11 with the VT-61/t forms and page editing terminal, and the VT-71 with embedded LSI-11 to do full file local editing. Both have some form of block transfer to the host, but as far as I can remember they used ordinary DH-11 terminal interfaces. DH-11 is unusual in that it has DMA in both directions, which is unhelpful for interactive use but great for block transfer. Typeset-11 also supported a specialized terminal made by Harris (the 2200), another local processor device, this one connected to the PDP-11 host with a DL-11/E, using half duplex multidrop BISYNC with modem signal handshakes. I kid you not... I have some scars debugging that protocol at 2 am in downtown Philadelphia. > > DEC also built yet another VT-51 variation, the VT-62, which was the terminal for the TRAX system. That was, I think, some sort of RSX derivative (-M+ perhaps, but I'm not sure), which made it to field test but was canceled before becoming an official product. Not sure why. > > paul > > > > > End of cctalk Digest, Vol 88, Issue 29 > **************************************

3 years, 3 months

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What was a Terminal Concentration Device in DEC's products?

by jnc＠mercury.lcs.mit.edu

> From: Paul Koning > DH-11 is unusual in that it has DMA in both directions McNamara's DH11? (I don't know of another DECdevice of that name.) Per: http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_1… it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU. Noel PS: I am familiar with the term 'terminal concentrator' from the networking world, but as a generic term, not the name of a particular product. (Although Cisco's first boxes may have included a terminal concentrator, so named.) Noel

3 years, 3 months

4
3
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What was a Terminal Concentration Device in DEC's products?

by cz＠alembic.crystel.com

Old question: I'm looking through some old reports from 1977 about a failed DEC project with the DMX11 multiplexer system and there is reference to the following key items: 1) The DMX was designed to handle block mode devices. Fine. 2) Character mode devices like the VT52's were supposed to use a "TCD" product from DEC. The reason the project imploded was because apparently DEC stopped supporting the TCD in RSX11/D in late 1976, so someone in CSS had the great idea of agreeing to extend the microcode in the DMX11 to handle both block AND character mode devices. This did.... not work well and it sank the project. What I'm wondering is what was the TCD for PDP11's back then? I don't see anything in my communications handbooks on this, and even the DMX11 doesn't really appear, instead there is the COMM/IO/P type boards which worked with a pile of DZ11's. From what I can glean from this documentation it looks like the DMX11 worked in a similar fashion as the requirement was the DMX11 system was a nine board solution (possibly 8 DZ11's and one controller board). More odd it looks like the TCD *was* still supported in RSX11/M and ultimately the decision was made to build the thing in M so it's weird they continued to whack away at the DMX solution instead of going with TCD's for async and proven DMX microcode for block devices. Any thoughts, or does this jog any memories? C

3 years, 3 months

2
1
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simulation of an entire IBM S/360 Model 50 mainframe

by decguy＠songdog.eskimo.com

This might be old news to a lot of people here, but I noticed a fun article on The Register today: Hardware boffin is building a simulation of an entire IBM S/360 Model 50 mainframe https://www.theregister.com/2022/01/27/ibm_s360_simulation/ The article has a handy link to a post on Ken Shirriff's blog: https://www.righto.com/2022/01/ibm360model50.html While I'm kind of a "DEC guy", I still have a certain nostalgic fondness for the IBM System/360, since that was my first in-depth exposure to computer programming.

3 years, 3 months

3
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Datum Front Panels

by wrcooke＠wrcooke.net

Some years ago I was on a mission to rack mount all my computer and test equipment. I found three front panels at a hamfest that I planned to use. I never did anything with them but still have them. These are from Datum systems, but they appear to be rather hard to find much information on. The short story is, if anyone needs them for something, let me know. I would hate to do away with them if someone needs them. Two of the panels are marked: Datum, inc Rotating Drum Memory 6008 Datum, inc Data Acquisition System 120 The last isn't marked. A picture is here: http://wrcooke.net/FrontPanels.jpg I will likely be moving in a few months and these are on the "get rid of" list. Thanks, Will

3 years, 3 months

2
1
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Question about DECtape formulation

by go＠aerodesic.com

I've always thought the physical tape wound on a DECtape spool was a fairly conventional 'sandwich' of mylar/oxide/mylar, but a recent 'test' makes me think there is something else involved. I have a number of tapes I'm cleaning (removing dust, etc.)? to make ready to read on a restored (apparently) Astrotype dual DECtape drive and I was 'dressing' the leaders of the tape (removing ragged bits from old use.)? After trimming a wee bit from several tapes (.5 to 1 inch) I did a test.? Taking the bits of tape, I exposed them to various concentrations of isopropanol/water (from about 25% to 99% iso) and found than in all cases, some of the data side of the tape came off on the wipe.? The remaining tape fragment appears intact - the brown oxide was still there but both sides were now the same color, rather than the data side being darker (as were all my tapes before the test.) Was there some kind of 'lubricating' coat on the data side?? It makes sense, but none of my DEC documents or Googling has any mention of lubrication, other than the "...hydro- dynamic lubrication, relying on the viscosity of air to entrain it with the tape and provide the flotation medium." found in an "ELECTROMECHANICAL COMPONENTS & SYSTEMS DESIGN" from November,? 1964. All of my tapes, including DECtape brand, Scotch brand and even a couple of old "Microtape" brand from DEC (before 'dectape' name change) have this feature, so this doesn't appear to be something that appeared recently (as in late in DECtape production or due to old-age in the tapes.) If someone has some detail information on the tape construction, I'd am curious to see it. Thanks,

3 years, 3 months

7
10
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2 microvax 3800's for sale

by lyokoboy0＠gmail.com

Hello, I had picked up these machines fresh out of high school. I actually worked a deal with the buyer to make payments out of my paycheck for a few weeks till they were paid in full. i have not had the time to focus and get them running. one machine i have had up to the cpu monitor, no internal disk drive. the second machine has some corrosion on the front panel board, where the battery leaked. it iminimal, and the bad battery is removed. open to offers. located in US Florida Looking to sell off excess stuff, i want to focus on my pdp11's and mainframes.

3 years, 3 months

4
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Searching for information reg. IBM 3979 (Expansion module for 3179G / 3192G coax (3270) terminal)

by romietoo9ibi＠xx.vu

Hi! I am the proud owner of a 3192G coax terminal. As I have recently learned, there is an expansion module for the terminal that allows you to attach a mouse and a IEEE-488 pen plotter to the terminal. Some information about it can be found at [1] and [2]. I am searching for people who are in possession of this expansion unit, out of interest how the PCB looks, etc. If you have one, please respond. -Alex [1] http://bitsavers.org/pdf/ibm/3192/GA18-2590-1_IBM_3192-G_Color_Graphics_Dis… [2] http://www.bitsavers.org/pdf/datapro/alphanumeric_terminals/Datapro_C25_IBM…

3 years, 3 months

1
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Old Micro Memory core board

by go＠ao-cs.com

Going through an old junk pile, I came across a couple of core boards: Micro Memory, Inc. PN 90360 8K*8 (MM-6800)? Date code 7725 I have two boards (s/n 202 and 203) so likely purchased in pairs. Anyone have any information on these?? They have 86 pin connectors so not S-100 though connector is about the same size. For years, these have sit on a shelf on my 'round tuit' list of bringing them up in one of my old S-100 boxes, so I've been cruising along thinking these were 100 pin connectors.? I got them out today so I could find the manual (I have used the MMI s-100 8kx8 boards in an old company project back in 1977 and those were about the same size and form.)? The core board is a daughter board on top of the board with the bus connector and is likely the same module from the S-100 board.? I'm guessing the 86 pin bus is a Motorola Exorciser bus - so I can probable figure it out from there, but I would like to find a manual. I think my company had an Exorciser development system in the late 70s.? These were obtained from a dumpster dive.? Pity I didn't get the rest of the box, if so. As usual, google wasn't extremely helpful with old pedestrian hardware searches. -Gary

3 years, 3 months

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Question about DECtape formulation

by jnc＠mercury.lcs.mit.edu

> From: Gary Oliver > I've always thought the physical tape wound on a DECtape spool was a > fairly conventional 'sandwich' of mylar/oxide/mylar ... > Was there some kind of 'lubricating' coat on the data side? It makes > sense, but none of my DEC documents or Googling has any mention of > lubrication ... > If someone has some detail information on the tape construction, I'd am > curious to see it. Dunno if you know of this: http://www.bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf but it doesn't mention any lubrication, just a "Protective Overlay" layer, over the "Coating" (which I assume is the oxide). I'm a bit surprised that "some of the data side of the tape came off on the wipe", though, unless the "various concentrations of isopropanol/water" dissolved the Protective Overlay. Noel

3 years, 3 months

7
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Typing in lost code

by mark.kahrs＠gmail.com

Has anyone ever used Amazon Mechanical Turk to employ typists to type in old listings of lost code? Asking for a friend.

3 years, 3 months

9
11
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mystery S-100 available

by sieler＠allegro.com

Hi, I have a mystery S-100 computer that I'm would like to sell, from the estate of the late Ken Gielow (author of Z80DIS, a great Z80 disassembler). The proceeds will be donated to a non-tax-deductible magic group Ken was a long-time member of. The computer is located in Cupertino, CA (aka "the heart of Silicon Valley", in the S.F. Bay Area). (If reopened, you can combine a pickup with a visit to the Computer History Museum in nearby Mountain View, CA! :) This would likely be quite expensive to ship. I'd guess 30+ pounds. Photos and some info at: www.sieler.com/ken_photos Some of the hardware (also listed on the above page): ThinkerToys buss unknown semi-transparent front panel spare/uninstalled Ithaca Intersystems DPS-1 front panel 10 various boards inside metal case (heavy) There may be manuals on some of the boards and/or the Ithaca, but I'm not sure yet. (They would be included, if they exist.) I wanted to take photos of each board, but having been seated for about 40 years, they don't come out if I tug gently. None have integrated board lifters, unfortunately (I tried a boroscope, but could not get useful photos.) Based on the labels on some EPROMS, there's a chance that it's a homebrew TRS-80 clone, with both Level II BASIC and CBASIC, and may have Morrow DISCUS software on it. We're looking for an offer on either: - the Ithaca Intersystems front panel; - the computer with all the boards or both. Suggestions welcome, thanks!

3 years, 3 months

2
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Question about DECtape formulation

by jnc＠mercury.lcs.mit.edu

> From: Gary Oliver > Paul - thanks for the bitsavers reference. Ahem! In any case, it's Al who really deserves the credit, for finding that document, and putting it up. Noel

3 years, 3 months

2
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Typing in lost code

by jnc＠mercury.lcs.mit.edu

> From: Gavin Scott > I think if I had a whole lot of old faded greenbar etc. ... Someone may > even have done this already See: https://walden-family.com/impcode/imp-code.pdf Someone's already done the specialist OCR to deal with faded program listings. Noel

3 years, 3 months

4
4
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PDP-8 clone built by Canadian company Consolidated Computer Inc

by rodsmallwood52＠btinternet.com

I am trying to locate documentation on the PDP-8 clone built by Canadian company Consolidated Computer Inc (Mers Kutt) in the mid 1970's. An example exists in the UK and will be restored when more data than just the system can be found. Rod Smallwood - digital equipment corporation 1975-1985

3 years, 3 months

1
0
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Compaq Portable brightness knob

by dave＠661.org

Would someone please suggest a replacement for the Compaq Portable's brightness knob? This was missing on mine when I got it. -- David Griffith dave at 661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

3 years, 3 months

3
5
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Building a BA08 for a pdp8/L

by cz＠alembic.crystel.com

So now that my pdp8/L is up and running (it now has a serial port and runs FOCAL69 quite well) I'm thinking about the next step, which is of course more memory. This requires a BA08 or BM8/L or something expansion box but to be honest I have enough spare flip chips and such from the wrecked 8/I to build about 3 core memory systems. So given that the schematics for the BA08 are online, they look pretty darn simple, I have the parts, and I have the parts does anyone know if it's possible to get a flip chip backplane to work on and wire up to emulate a BA08? It looks like they just used the data break interface lines to hook up to the processor. Everything's there, Memory address bus, memory data bus, and the various signals for jumps and the like that could allow one to decode and implement the extra instructions needed. Hm. Might just be easier to build it with an FPGA or something as it's mostly linking up simple gates and the whole core memory section could be removed by a 4k*12 memory array. Anyone ever done this? C

3 years, 3 months

2
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VAX 780 on eBay

by jnc＠mercury.lcs.mit.edu

> This: > https://www.ebay.com/itm/275084268137 > ... > Anyway I fully expect it to go ... for a _lot_ more than the opening price. Much to my surprise, it didn't sell at all (although a number of other lots, likely from this machine, did.) I'm rather puzzled that an -11/70 will sell for north of $10K, while a /780 can't fetch $5K. I can only guess that PDP-11'S are seen as more important in the collector world (even though the BSD work, which had such a huge impact on UNIX, which has now - in the form of Linux - taken over the world, was centered on the VAX). Noel

3 years, 3 months

6
6
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WARNING: Clear QIC Tape Bands

by lists＠glitchwrks.com

https://i.imgur.com/48EfOQG.jpg That's after sitting parked a couple months. I have a Dysan doing it too. The Dysan had been re-banded with a boiled 3M band and run for years like that with no shedding. I have another Dysan with a green Plastiband in it which is also fine, minimal/no shed. So, I think we may need to re-evaluate if the clear Amazon cheap "plastibands" are perhaps totally incompatible with tape. I know, I know..."just use the band to get data off." But I want to *run* QICs without having to destroy them constantly. Thanks, Jonathan

3 years, 3 months

9
21
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Source for replacement caps in H744 regulators

by robert.jarratt＠ntlworld.com

I think I may need to replace the two output capacitors in some of my H744 regulators. These are screw terminal 6,000uF 10V parts. I have looked on Mouser, Farnell and Digikey and there don't seem to be any available, and any that are listed are really rather costly. Does anyone know where I might find some, preferably from a reputable supplier. Note that I am in the UK. If I can't find 10V rated ones, then, generally up to what sort of voltage rating can I go? Of course, physical size will be a factor, but electrically can it affect operation of the regulator if the rated voltage is too high? Thanks Rob

3 years, 3 months

13
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Tiny PDP-11/73 system for sale

by stephen.m.pereira.sr＠gmail.com

I am in the process of thinning down my vintage computer holdings, to relieve some of the burden I will leave to my heirs (hopefully not too soon!). I have a working tiny PDP-11/73 system available for sale. I would much prefer not to have to break it down and pack it for shipping, but I will if the buyer agrees to pay for the packing and shipping costs. - - - - - Tiny PDP-11/73 System: H9281-BA backplane and card cage KDJ11-A CPU DLV11-J 4 port SIO MSV11-LK 256KB/128KW memory Emulex UC07 SCSI interface Power-on Reset board from here: http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por SCSI-to-SD hard drive emulator with 4 drives available, RT-11 installed MeanWell RT-125B power supply 4.5 inch AC fan qty 4 GlitchWorks serial cables Spare PDP-11/23 CPU saved as a backup: KDF11-AB CPU RT-11 Pocket Guide RT-11 Mini-Reference Manual - - - - - I am asking $800.00 for the lot. It cost me about that, probably more to acquire it piece-by-piece and assemble it into a working system. smp - - - Stephen Pereira Bedford, NH 03110 KB1SXE

3 years, 3 months

1
1
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Screws for a Compaq Portable keyboard

by dave＠661.org

Would someone please suggest a suitable screw specification for the Compaq Portable keyboard? My restoration project was interrupted and I managed to lose the screws. -- David Griffith dave at 661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

3 years, 3 months

1
0
0 0

DECnet/10 manuals?

by paulkoning＠comcast.net

I'm looking for a manual I can't find on Bitsavers: a DECnet/10 programming manual. The reason: trying to read PSTHRU.MAC and realizing that I was trying to understand DECnet-10 code while reading the DECnet-20 programming manual. Oops. paul

3 years, 3 months

1
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Tiny PDP-11/73 system for sale

by stephen.m.pereira.sr＠gmail.com

I am in the process of thinning down my vintage computer holdings, to relieve some of the burden I will leave to my heirs (hopefully not too soon!). I have a working tiny PDP-11/73 system available for sale. I would much prefer not to have to break it down and pack it for shipping, but I will if the buyer agrees to pay for the packing and shipping costs. - - - - - Tiny PDP-11/73 System: H9281-BA backplane and card cage KDJ11-A CPU DLV11-J 4 port SIO MSV11-LK 256KB/128KW memory Emulex UC07 SCSI interface Power-on Reset board from here: http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por <http://www.heeltoe.com/index.php?n=Pcbs.Qbus-por> SCSI-to-SD hard drive emulator with 4 drives available, RT-11 installed MeanWell RT-125B power supply 4.5 inch AC fan qty 4 GlitchWorks serial cables Spare PDP-11/23 CPU saved as a backup: KDF11-AB CPU RT-11 Pocket Guide RT-11 Mini-Reference Manual - - - - - I am asking $800.00 for the lot. It cost me about that, probably more to acquire it piece-by-piece and assemble it into a working system. smp - - - Stephen Pereira Bedford, NH 03110 KB1SXE

3 years, 3 months

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Sun 3/260 on eBay; Boston area

by pschow＠gmail.com

Local pickup only. https://www.ebay.com/itm/265510502961

3 years, 3 months

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seeking Motorola M68MM01A2 documentation

by chrise＠pobox.com

I have quite a few Motorola Microsystems Exorciser boards including this 6800 single board computer for which I am lacking any documentation. I've seen a brochure in Al's collection on Bitsavers but haven't found any details that might discuss jumper settings or even better, a schematic. Wondering if anyone would have a user manual or other detailed docs for this board? M68MM01A2 -- has 6800 CPU, 6875 1.0 MHz clock generator, 6850 ACIA and MC14411 baud rate clock, (4) EPROM/ROM sockets and (2) 6821 PIA sockets with the 86-pin Exorciser edge connector. I'm interested in seeing if I can minimally modify it to have a similar memory map to the Altair 680 so that the Altair's PROM monitor could run on it. Thanks! Chris -- Chris Elmquist

3 years, 3 months

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AOL diskettes

by athornton＠gmail.com

> From: Grant Taylor <cctalk at gtaylor.tnetconsulting.net> > > I wince at the idea of running with QIC tape. But my experience is with > QIC-80 tapes of the '90s which were so unreliable as to be in the same > category as AOL floppy disks during the late '90s around the transition > to CD-ROMs. As in I would trust an AOL floppy disk to better hold my > data for a week than I would a QIC-80 tape to hold data for a month, > much less a year. ...and I didn't even trust an AOL floppy to go from > computer to computer for 5 minutes. -- Talk about a race to the bottom > for quality. I wish I'd kept some. I had some AOL CDs from slightly later that made decent coasters for decades. Although I guess with the shutter, the floppy wouldn't really have made a very good coaster. Adam

3 years, 3 months

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IBM 6731 Diskette Module

by organlists1＠sonic.net

Is anyone familiar with the IBM 6731 Diskette Module from around 1984 which gave the IBM Electronic 85 and 95 Selectric Typewriters the ability to store created documents to a 5.25" floppy diskette? There was also a 5.25" diskette which was nicknamed "IPL" for "initial program load", and an interface board which was installed into the typewriter and was referred to as the "IBM Typewriter Modularity Option". I do not have any images of the IBM 6731, but I do have an image capture >from the installation and operations manual, posted here: https://www.dropbox.com/s/us8aely530s8p3a/6731diskettemodule.jpg?dl=0 You do not need a Dropbox account to view the image. Simply click on the X of the login pop up and it will disappear. Unfortunately, the only copy of this product manual I ever found was on eBay. I purchased it last month, paid USPS priority mail shipping with tracking and the post office lost it. :/ Thanks Don Resor

3 years, 3 months

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IBM 6731 Diskette Module

by organlists1＠sonic.net

Is anyone familiar with the IBM 6731 Diskette Module from around 1984 which gave the IBM Electronic 85 and 95 Selectric Typewriters the ability to store created documents to a 5.25" floppy diskette? There was also a 5.25" diskette which was nicknamed "IPL" for "initial program load", and an interface board which was installed into the typewriter and was referred to as the "IBM Typewriter Modularity Option". I do not have any images of the IBM 6731, but I do have an image capture >from the installation and operations manual, posted here: https://www.dropbox.com/s/us8aely530s8p3a/6731diskettemodule.jpg?dl=0 You do not need a Dropbox account to view the image. Simply click on the X of the login pop up and it will disappear. Unfortunately, the only copy of this product manual I ever found was on eBay. I purchased it last month, paid USPS priority mail shipping with tracking and the post office lost it. :/ Thanks Don Resor

3 years, 3 months

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Looking for CONAR CCTV TV camera CONAR WERE KITS FROM NATIONAL RADIO COMPANY

by couryhouse＠aol.com

Looking for CONAR CCTV? TV camera CONAR WERE KITS FROM NATIONAL RADIO COMPANY want books parts assembled units whole units? broken units-- I lust for one in the box un-assembled too! anything anything anything? related? toi this? camera? collecting up stories and folklore from others that may have? built one, owned one or? even just lusted? for? one!reply using the? following? ??SMECC CONAR TV CAMERA HISTORY PROJECT?? ? ?as? email reply? title? and? send? to?couryhouse at aol.comdrop me a line off list? with? first? word? CONAR? in subj. line? thx....Thanks in advance and stay well....Ed Sharpe? Archivist? for? SMECC

3 years, 3 months

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