test-drb

test-drb@ccmp.vtda.org

101090 discussions

by healyzh＠avanthar.com

I really want to see this set produced, especially for the ?Ada Lovelace? and ?Admiral Hopper? portions of the set. https://ideas.lego.com/blogs/a4ae09b6-0d4c-4307-9da8-3ee9f3d368d6/post/f39b… https://ideas.lego.com/projects/3bf5b46c-6c87-4a2d-a2e1-d31ed0e2739e Zane

4 years, 3 months

External SCSI Drives on DEC2000 AXP

by g4ajq1＠gmail.com

I am trying to format a couple of SCSI drives on the Alpha.? They are connected using the external cable and are mounted in an Open Storage Systems (OSS) box. The drives were working when removed from a PC. SRM shows only one of them coming up as DKA200.? I have set the two drive ID switches to 2 and 3. Lack of info is hampering me, I have gleaned form various sources that the following command should work: >>>t scsi format a 2 0 which just returns >>>OK immediately, without doing anything. VMS allows me to ini the disk, but then when I try to mount it, I get an operator services message saying it is offline, please mount volume in _$3$dka200: Anybody with experience here? cheers, Nigel -- Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU Amateur Radio, the origin of the open-source concept! Skype: TILBURY2591 nw.johnson at ieee.org

4 years, 3 months

cctech Digest, Vol 87, Issue 3

by w9gb＠icloud.com

Power Supplies, due to their Weight, are placed at the bottom of Racks (prevent tip overs ? weight distribution). https://avitech.com.au/?page_id=366 The PDP-11/70 Maintenance and Installation Manual (EK-11070-MM-002) explains that the basic PDP-11/70 system components are located in a double cabinet as shown in Figure 1-1 of that manual. https://i0.wp.com/avitech.com.au/wp-content/uploads/2016/05/major-assemblie… greg > Date: Sat, 4 Dec 2021 19:28:01 -0800 > From: Marc Howard <cramcram at gmail.com> > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > Subject: Need picture of power supply mounted in 11/40 cabinet > > Hi, > > I've got an 11/40 I'm going to start working on. Problem is that there are > two power supplies (H742 and H7420) that came with it but neither was > mounted in the rack. > > Could someone post/send/etc. photos of how the power supply mounts in the > rack? Also how is the power cabling routed (I think I'm missing this part)? > > Thanks, > > Marc Howard

4 years, 3 months

Disk cartridge storage racks

by Flash688＠flying-disk.com

I am in need of some disk cartridge storage racks. The kinds I am looking for are the ones used for front-loading cartridges (IBM 2315, DEC RK05, etc.) as well as the ones for top-loading cartridges (IBM 5440, DEC RL02, etc.). They were typically made of welded wire, and stored the cartridges on edge. I could use either the free-standing ones that sit on a shelf, or the ones that were designed to go in a Wrightline cabinet. I am in northwest Oregon and am willing to drive anywhere in the neighboring states to pick them up, or pay for packing and shipping. Thanks, Alan Frisbie

4 years, 3 months

Testers with Alpha or DECstation hardware with framebuffers?

by abs＠absd.org

I've been trying to fixup NetBSD to build usable X servers from up to date Xorg for Alpha and MIPS based DECstations, and wondered if anyone on list had any machines to hand on which they might be willing to test? There is a full distribution (individual set files and bootable ISO image) in http://sync.absd.org/xwsfb/ - the README from that directory is included below. If anything is non obvious, or it would help to have test images in a different format, just let me know Thanks David xwsfb - v1.2 This contains wsfb Xorg builds for NetBSD/pmax and NetBSD/alpha from 2021-12-03 sources Changes from stock NetBSD tree: - Add WSDISPLAYIO_GET_FBINFO to dev/tc TURBOchannel display adaptors - Enable building Xwsfb X server for pmax - Switch alpha from Xorg 1.10 to 1.20 (plus tweaked bsd_ev56 from 1.10) - (diffs in xwsfb.diff) Things to test: - Any and all framebuffers, TURBOchannel (and also PCI on alpha) - Confirm if keyboard mapping is correct (and does console match x11) - Does uxterm work on alpha pmax issues: - uxterm and LC_CTYPE=en_US.UTF-8 in general do not work - Escape does not work on gxemul console (not a regression from stock) To install and test pmax in gxemul - Install gxemul :) - eg pkgsrc/emulators/gxemul - Create a 2GB disk image: dd if=/dev/zero of=pmax.img bs=1m count=2048 - Run: gxemul -X -M 256 -e 3max -d pmax.img -d b:NetBSD-9.99.92-pmax.iso - Follow prompts to install - At the end - select 'Add a user' and make sure it is added to wheel - Exit and halt - Run: gxemul -X -M 256 -e 3max -d pmax.img (wait ~forever for fontcache) - Login as root, edit /etc/X11/ctwm/system.ctwmrc and change "uxterm" to "xterm" - Run: startx - Optionally: (if user is in wheel group), enable xdm=YES in /etc/rc.conf To upgrade an existing NetBSD-9.99.92 install - Ensure you have the following from this location (where arch is alpha or pmax) - ${arch}/binary/kernel/netbsd-GENERIC.gz - ${arch}/binary/sets/xbase.tgz - ${arch}/binary/sets/xcomp.tgz - ${arch}/binary/sets/xetc.tgz - ${arch}/binary/sets/xfont.tgz - ${arch}/binary/sets/xserver.tgz - Copy /netbsd to /onetbsd, then extract netbsd-GENERIC.gz as /netbsd - Wipe /usr/X11R7 then extract x*tgz from / - For pmax only: edit /etc/X11/ctwm/system.ctwmrc & change "uxterm" to "xterm" - Run: startx - Optionally: (if user is in wheel group), enable xdm=YES in /etc/rc.conf

4 years, 3 months

Women of Computing

by jnc＠mercury.lcs.mit.edu

Can we please return to discussions of actual classic computers, before our long-suffering list host shuts the list down _again_ for this sort of argument, this time perhaps forever? Thank you. Noel

4 years, 3 months

Source for DEC TC01 (and similar) bulbs?

by derschjo＠gmail.com

Anyone sitting on a pile of these or know where to find some? These were originally Dialco 507-3917 or Drake 11-507 based on what was installed in mine. 24V, 40mA, white. A total of 23 bulbs were dead on my TC01's panel. I've installed a pile of electrically/physically compatible bulbs that I happened to have, but they're yellow/orange and have a different visual design (the yellow lens sticks out 1/8" or so, whereas the orginals were flush). I'm honestly fine with using them but it'd be nice to have something that looks original. And a small progress update: Found that the IOT decode for READ STATUS B wasn't working, which is done on the W103 decoder at E/F19. With that resolved the diagnostics are behaving much more rationally. This took me much too long to trace down, but I learned a lot about how the controller works and found a fun (but ultimately harmless) bug in the Basic Exerciser diagnostic that threw me off for a couple of days... The Search Scope loop diagnostic shows block numbers going by in both directions so a lot of the drive and controller are working, but there's some glitchiness in bits 2, 5, 8, and 11 of the data so I need to trace that down; I hope it's not the tape head. - Josh

4 years, 3 months

alt.folklore.computers... Altair Bob

by wh.sudbrink＠verizon.net

A very, very long time ago, when dinosaurs still roamed the earth (or at least the computer rooms) there was a guy on usenet who called himself "Altair Bob" and offered to buy Altair computers. This was back when they weren't worth all that much (mid to late 1980s). He must have bought a dozen or so (as I remember). Does anybody know who he really was and what became of his (what I'm assuming was a) collection? Just idle curiosity brought on by a recent discussion of collections being destroyed by widows. Bill S. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

4 years, 3 months

pdp8/L restoration time, part 1: switches

by cz＠alembic.crystel.com

I've decided it's time to fix my second pdp8/L. First one is missing (I think it's at the bottom of the closet) so I'll work on this one for awhile. First problem: Testing the lamps and switches. If the switches don't work or the lamps are out it's not going to be easy to troubleshoot. Currently I'm missing 5 of the plastic switches, and I have 2-3 switches with a broken pivot. Since I was going to need new plastic switch covers I fired up the 3d printer, downloaded the STL file for making them (thank you for putting that up!) and ran off a few for testing. It helps a lot to set the bridge angle value to 60% or so, that allows a nice solid bridge for the two "teeth" that engage the rocker switch. Also don't bother with PLA: The plastic pivots are too weak and break pretty quickly. Use PETG, which requires higher heat (240 instead of 200 at the head and 70 instead of 60 at the base) but it is more than strong enough for the pivots to go in without issues. Testing the switches I found that one of the data/address switches was reading high ohmage (20) when closed in the down direction and two of the data entry (spring loaded) switches were intermittent. Sprayed in a bit of Deoxit, and they now switch cleanly and without bounce. That would probably have driven me crazy if I tried to test with that. Next step: Check out the power supply..... C

4 years, 3 months

Datapoint 2200 on ebay

by osi.superboard＠gmail.com

In my opinion, the Datapoint 2200 on ebay seems to be a 1100 Cassette Terminal. There are two theories - It is a true 1108, as the silver machine label indicates. This 1100 versions showed up in 1974 as described by the LCFGROUP and have been a variant to the 2200 with less memory , using most of the 2200 parts, except the power supply at the back. This has been re-designed. The Datapoint 2200 on ebay is most likely a 1100. But it has the 2200 logo at the front, how can this be ? Ken Whitehead may have the answer for that: StaTuesday 17th July 2012 Ken Whitehead (USA) Other comments re: confusing the 1100/2200/5500/6600 may have arisen >from the fact that all of the enclosures for these models started life with 2200 molded into the plastic bezel. The 1100, 5500 and 6600 models had a separate logo that was applied over the existing 2200 logo. Since double-stick foam tapes were used, over time the tape let loose and the ?new? logo fell off. We had a few customer complaints re: the instant downgrading of their computers when this happened! Alas, we know that for all of those that complained, many more didn?t, giving possible rise to the confusion of what the machine actually was. - My second theory is, it is one of the 1100 terminals, that have been upgraded to a 2200, yes that was possible. The Dataform_1100_Brochure_1974 says: System Expandability. The 1100 user need not fear an application outgrowing an 1100's capabi lit ies. If additional data input locations are required, the 1100 can be upgraded to a Datapoint 2200 DATASHARE System. Seems this was offered along the introduction of the 1100, about 3 years after market introduction of the 2200.With this upgrade came extra 8kb more memory (2 more RAM boards) and a new front cover or removal of the 1100 logo plate ? In any case it is not a Datapoint 2200 as advertised. A real 2200 looks like this: http://datapoint.vintagecomputers.square7.ch/index.html Anyone with another good explanation ? Thomas Sun Nov 28 13:27:20 CST 2021 Previous message: Micro Technology Board Info Next message: Datapoint 2200 on ebay Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] Noticed a Datapoint 2200 on ebay.... https://www.ebay.com/itm/275043446827 They're asking $48,000 I want one...but not for that price! :) Previous message: Micro Technology Board Info Next message: Datapoint 2200 on ebay Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] More information about the cctalk mailing list

4 years, 3 months

What happened to control-data.info and controlfreaks.org?

by jim＠deitygraveyard.com

Is anybody able to access these sites? I just get redirected to Google. Jim

4 years, 4 months

Looking for someone in London (UK) to read 2 9 track tapes

by cclist＠sydex.com

Hey list, I received a note today from a fellow in London who has 2 9-track tapes that he'd like read. Brands are CDC and BASF, so media shedding should not be a problem. Dates are '92 and '93, so likely 1600 or 6259. The tape seal on one (the other has no seal) is IBM-style, which may be the system that produced the tapes. Any takers? Let me know if so, I'll put you in contact and you can take things from there. All the best, --Chuck

4 years, 4 months

PDP-11/70 Boards

by jnc＠mercury.lcs.mit.edu

> From: Guy Sotomayor > I don't unfortunately have any light masks Dave Bridgham and I were manoeuvreing to be able to produce clones of the one you loaned me (he has access to a computer-controlled milling machine at his maker-space or whatever the name is for them now, and we bought a good-sized sheet of the required plastic to be able to crank them out) when I came down with COVID early in the pendemic, and in the aftermath (I came down with long-haul post-COVID Chronic Fatigue Syndrome) itgot put on hold. The loaner, and a micrometer to measure it, are still siting on the table in my family room, next to my desktop. If anybody needs some, I can probably try finishing the drawing, and get it to Dave, so we can resume that project. Noel

4 years, 4 months

PDP-11/70 Boards

by jnc＠mercury.lcs.mit.edu

> From: Ed Cross > I'm currently restoring a PDP-11/70 system and need the following > boards to complete the CPU: FP11-C >From your mention of the FP11-C, I gather your -11/70 has a KB11-C (later) CPU, not the KB11-B CPU of the earlier PDP-11/70's (prior to 1976 - the difference between the two was whether they took the optional FP11-B or FP11-C FPP). Not that it makes a big difference in your case; the 4 cache cards are the same in both. There used to be a seller on eBait (on the mid-East Coast - Baltimore, IIRC) who was selling -11/70 CPU cards (I bought a whole spare set from him) but alas he seems to have gone away (or sold them all; a quick search, both on eBait, and in my email, didn't turm him up; I can institute a deeper search if need be). >From the blog of someone who got a KB11-A working, you'll really need KM11 cards; dunno if Guy Steele still has those clones he was selling. There are definitely some versions of Unix which will run fine on -11/70's without the FP11 (e.g. V6). The system binary is different for the with/without versions, though: in the assembler code which saves the state of one process before switching to another, there is code like: stfps (r1)+ which will probably get an illegal instruction trap in kernel mode on a machine with no FP11, and is therefore conditionally assembled (depending on if the particular machine the system is being built for has an FP11). Perhaps the later BSD versions look for the FP11 on startup, and adjust their behaviour appropriately, but I'm not familiar with them. V6 as distributed contains system binary for an -11/40, which will run on _any_ -11 UNIX will run on, and can be used to build appropriate system binary. (Diversion: I've never found out whether the KB11-B and KB11-C of the -11/70 used/could use the same backplane or not. By examining the prints for the boards of the FP11-B and FP11-C, and seeing on which pins they exchanged signals, and what signals they exchanged with the rest of the CPU, and on which pins, it should be possible to work it out. Ditto for the M8133 ROM and ROM Control of the KB11-B, replaced with the M8123 in the KB11-C.) (Interesting factoid: the M8123 is the only card shared between any variant of the -11/45 and -11/70: both the KB11-C and KB11-D use it. Of course, I think we're still missing a wirelist for the -11/70 backplane, of any variant; and the ECO history. There appears to have been at least one poorly documented upgrade; see here: http://gunkies.org/wiki/MK11_memory_system#CSR_Access for more.) Noel

4 years, 4 months

Looking for tips debugging DEC TC01 controller

by derschjo＠gmail.com

Hey all -- I picked up a TC01 in trade (for a TC08) a couple of weeks back and this past weekend I got it hooked up and powered up with my PDP-8/I + TU55 transport. I've been debugging it and have solved a couple of issues but the current one has me stumped and I'm looking for advice, hoping I overlooked something obvious. At this point the PDP-8/I can talk to the TC01 and use it to control the TU55 without issue. I've mostly been using MAINDEC-08-D3BB to exercise the hardware (see: http://svn.so-much-stuff.com/svn/trunk/pdp8/src/dec/maindec-08-d3b/maindec-…) and issuing FWD/BACK commands via the "Basic Motion" routine the tape runs >from one end of the tape to the other, stopping at the endzones correctly. The tape comes up to speed properly, the COUNTER register increments, and in general the various status lights on the panel do what I expect them to do. The root symptom I'm seeing now is that DECtape operations (like SEARCH) don't complete, and I've traced this back to the MK BLK MK signal not getting asserted. This signal is generated by a large AND gate (see p. 112 of http://bitsavers.trailing-edge.com/pdf/dec/dectape/tc01/DEC-08-I2AB-D_TC01_…). This gate ANDs together a pile of signals from the WINDOW register and the counter, looking for a specific bit pattern on the mark tracks; this AND gate is never satisfied because the WINDOW register's MSB (W1) is stuck low. On the scope it's a completely flat line, no glitches or anything noticeable. Despite my best efforts I cannot figure out why this is. Here's what I've looked at and what I've discovered thus far: 1) The inputs to the W1 flip-flop (pins U (clock) and V (data) look to be correct -- U is identical to the TP1 signal being passed to all the other flip-flops in the chain, and V is identical to the data coming out of W2 -- levels all look fine. 2) The outputs of W1 (pins T and S) are not being pulled up or down by anything external. I've gone so far as to completely disconnect T and S >from the backplane (with some tape over the card fingers) and the outputs are still a flat line. 3) The output of pin T goes to -3V when 0->WINDOW is de-asserted (when tape is in motion), returns to 0V when 0->WINDOW is asserted after the tape stops. (S is the inverse of this, as expected.) (As an aside, the schematic drawing suggests that 0->WINDOW ought to be a pulse given the arrow symbol; this does not appear to be the case. Other flip flops in the chain seem to behave properly, regardless...) 4) The backplane connection to the R203 flip-chip that the W1 flip-flop is on is fine. I've beeped this out and there's no significant resistance between the backplane pins and the connection to the card in the slot. 5) W1 is not affected by the state of the two other flip flops on the R203 (also tested by disconnecting all pins other than power/gnd and pins R/S/T/U/V with tape). 6) Swapping in a different, working R203 shows no change in behavior. 6) Sometimes, randomly, W1 starts working. Last night I noticed that the solder side of R203 was rubbing against the top of the "flip chip" packages on the R107 next to it and even though those shouldn't be conductive, I stuck a piece of cardstock between the two. W1 started working! I tested things for about a half hour in this state (interrupts were still not occurring, much to my annoyance) and this morning I powered it up and it was still working. Pulled the cardstock out and W1 stopped working; this would seem to causation. Put the cardstock back in... still won't work. Backplane connections all test out fine (see (4) above). Put the R203 on an extender (to completely avoid interference with neighboring cards) and still no go. Possibly the insertion of the cardstock flexed the board or the connection with the backplane slot ever so slightly to make things work but if so I've been unable to replicate it. All of this still sounds like a bad connection somewhere (backplane, cold solder joint, broken trace) but the evidence seems to be against it (checked, double-checked, triple-checked backplane, swapped R203s around, etc...) Anyone have suggestions? I'm going to start looking at things on the board itself (which is going to be a pain given how things are currently arranged in the chassis) but curious if I've missed anything here... - Josh

4 years, 4 months

Datapoint 2200 on ebay

by sieler＠allegro.com

Noticed a Datapoint 2200 on ebay.... https://www.ebay.com/itm/275043446827 They're asking $48,000 I want one...but not for that price! :)

4 years, 4 months

PDP-11/70 Boards

by edcross＠gmail.com

Dear list, I'm currently restoring a PDP-11/70 system and need the following boards to complete the CPU: FP11-C slots: M8127 M8128 M8129 Cache slots: M8142 M8143 M8144 M8145 Any help finding these is appreciated. Thanks.

4 years, 4 months

3483 + LCD

by ben＠huntsmans.net

Hi guys- Anyone on here have any experience using an IBM 3483 terminal with an LCD? I have an IBM 15" LCD I am hooking up to it, but parts of the image are below and above the viewable area of the display, and the characters look all garbled or like they're missing some lines. Auto-adjust makes it all visible for a short second, and then it pops back to the way it was. I'd seen at least one other mention of this on the internet, but was wondering if anyone knew of any specific LCD's that are known to work with the 3483. Thanks in advance! -Ben

4 years, 4 months

Interesting emulex manuals. Keep, scan, or junk?

by cz＠alembic.crystel.com

Have some original Emulex manuals. Need space do people want them or trash? tc0551001 TC05 controller manual. I have Rev C, bitsavers has F pd9951002 I have Rev A Bitsavers site has rev D px9951902 Diagnostic distribution kit I have Rev E and H sc0351001 SC03/B1 technical manual. Bitsavers doesn't have sc0251001 SC02/A RP02/03 manual Rev H Bitsavers doesn't have I'll scan the SC03/B1 and SC02/A manuals, but does anyone want the rest? C

4 years, 4 months

What happened to control-data.info and controlfreaks.org?

by petermallan＠gmail.com

On 11/81/21,. Andrew Warkentin via cctalk <cctalk at classiccomp.org> wrote: >> What happened? Looking back at my emails, the list was operating normally >> until September 3. Then it just stopped. There were normal discussions >> going on. There was no flood of spam. As far as I can tell, nothing occured >> that would trigger a rage quit. >> >> Is the software and documentation that was on the site at least archived >> elsewhere? Has anybody downloaded it and can maybe upload to archive.org? >> >> Mike >> > I downloaded some of the software and documentation from there a long > time ago and still have it, although I didn't actually scrape the > entire site. I can upload what I've got to archive.org. > > The disk image kit of NOS 2.8.7 with CYBIS has been mirrored at > <https://codex.sjzoppi.com/doku.php?id=utilities:start> and most of > the documentation for it is available from the Wayback Machine at > < http://web.archive.org/web/20210421202420/http://www.control-data.info/Cybi… > I have a working version of NOS 2.8.1, but I would like to be able to add software that is not included as part of the system that I downloaded from controlfreaks.org about 18 months ago. An example might be the ALGOL68 compiler. (I stress 'might be', as I haven't checked if that is on my system already. I just know there is 'some good stuff' that I want and which I don't have.) I have had a look on archive.org, but I can't find anything that looks like CDC NOS software tapes. A big part of my difficulty is likely to be that I don't have a list of what was available on controlfreaks.org in order to be able to do a detailed search. I did search archive.org for controlfreaks.org, but all I get is Controlfreaks.orgAuthorized Users Only This site is for the research into historic systems and software made by Control Data Corporation. If you think you can contribute, email to ControlfreaksAdmin <https://web.archive.org/web/20210421192919/mailto:thunter0512 at gmail.com> to request a username/password for access to this site. All the content is over in the TWiki <https://web.archive.org/web/20210421192919/http://www.controlfreaks.org/twi…> . When I click on the TWiki link, I get {ScriptUrlPath}/view/TWiki/TWikiRegistration which is not much use. Does anyone have a list of the CDC software that was available from controlfreaks.org? Cheers Peter Allan

4 years, 4 months

Re: IBM transistor replacements

by alsilisk＠icloud.com

Thank you all for your responses and the leads you have given,??Responses to some of your questions and some more questions:?"Have you checked/measured whether they're actually faulty?"?Yes I have, in the picture I have provided on the bottom there are the ends of 3 transistor leads. This was one that fell off as I removed the card and by far the worst corroded, so despite the fact that the rest still work. I need to replace this one.?"?I would suspect that these transistors are pre-drivers for the power transistors and may not be super critical to get an exact replacement."?Would an NPN or PNP with the same HFE suffice, or do I need to know more? Forgive me but I am a complete idiot when it comes to this kind of circuit design and their tolerances.?"Did you get manuals with the printer?? If so it should have ALDs (schematics)."Unfortunately not, and nor can I find any online.?"The 3286 printers and 3277 terminals where infamous for intermittent problems"Excellent, glad I bought something that will provide the true IBM experience.?Thank you,?Al?

4 years, 4 months

IBM transistor replacements

by w9gb＠icloud.com

Al - The Texas Instruments (TI) 139 is likely a 2N139 PNP (BJT) transistor, capable of high speed switching (in that era). The 2N139 was originally an RCA transistor (tall cylinder) found in RCA and GE transistor radios (455 kHz IF section). The TI versions were low profile metal case, TO-33 case (8.5 to 9.5mm diameter) greg == From: Al <alsilisk at icloud.com> To: cctalk at classiccmp.org Subject: IBM transistor replacements Dear all, A while ago I received an IBM 3286 printer, annoyingly some of the transistors in the printer section have been corroded. What I am having trouble with is reading the part codes and finding a modern equivalent of them. One has a Ti logo and two sets of numbers (attached). Does anybody know which numbers are the part numbers and if they are IBM house numbered? Photos of the Ti transistors and card assembly: https://drive.google.com/drive/folders/1JTnsWS4A8NrYJNFsqK2ejOeqqJNjoF1w?us… Thanks in advance, Al

4 years, 4 months

Micro Technology Board Info

by g-wright＠att.net

Have this board here, but can't find any Info on it. Says Neptune board on the silkscreen, tag say model MSD138 T devDates are about 1990 to 1992. https://www.dropbox.com/s/uu8x7bc5a08jw90/IMG_2200.jpg?dl=0 https://www.dropbox.com/s/e8z542sdnusjpqa/IMG_2201.jpg?dl=0 https://www.dropbox.com/s/xql6w5zhiismbel/IMG_2199.jpg?dl=0 - Jerry

4 years, 4 months

IBM transistor replacements

by alsilisk＠icloud.com

Dear all, A while ago I received an IBM 3286 printer, annoyingly some of the transistors in the printer section have been corroded. What I am having trouble with is reading the part codes and finding a modern equivalent of them. There are two types. One has a Ti logo and two sets of numbers (attached). Does anybody know which numbers are the part numbers and if they are IBM house numbered? Photos of the Ti transistors and card assembly: https://drive.google.com/drive/folders/1JTnsWS4A8NrYJNFsqK2ejOeqqJNjoF1w?us… The other is an IBM transistor with what appears to be a 3 digit part code; for which I have been pointed to a list of house numbering and equivalents on the 1401 website. I was told the list is much older and I fear it might be out of date. However there is an entry for the part codes on my IBM transistors. Should I trust the list for replacements? http://ibm-1401.info/BobEricksonIBM-Transistor-Substitution.html Thanks in advance, Al

4 years, 4 months

K12MIT on PDP-12

by cc＠informatik.uni-stuttgart.de

So, with the help of you here, I was able to create OS/8 LINCtapes and to run SerialDisk. Everything runs very fine. Now comes the next thing: I want to have K12MIT, and it is no problem to compile or load the program. *But*: When I start K12MIT I don't get the prompt. I see the welcome message, and it correctly identifies the machine as a PDP-12, but that's it. As I've found out it apparently overwrites its code, the processor is looping around address 3600-3620. Examining the memory reveals that the code at 3600 has been overwritten with junk. So it's clear that it won't run anymore. What happens? Was anyone else able to run K12MIT on a PDP-12? BTW the same binary runs fine on a PDP-8, be it a real machine or SIMH. Christian

4 years, 4 months

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test-drb