test-drb

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101090 discussions

by robert.jarratt＠ntlworld.com

I am going to be moving on to testing some H745 regulators. If I understand the schematic correctly the +15V input is the reference voltage used to regulate the -15V output, is that correct? If so, then presumably it doesn't need a whole lot of current, is that right? Thanks Rob

4 years, 2 months

Retro Chip Tester Pro, US shopping basket?

by wh.sudbrink＠verizon.net

In response to my wife's "Buy yourself a Christmas present" direction, I've ordered a Retro Chip Tested Pro board. When you purchase the board, you get a BOM and links to stored shopping baskets for some European vendors. Has anyone built this in the US and stored their basket with a US vendor? Rev 1.2k by the way, but any basket would be helpful as the BOM differences between the versions are listed. Thanks, Bill S. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

4 years, 2 months

Question about SIMH Sigma-7/9 emulation

by dfnr2＠yahoo.com

Hi all, I see that SIMH incorporates the 32-bit Xerox Sigma architectures.? The Sigma 8/9/5x0 architectures are commented out but compile fine? Does anyone know if those later architectures have known issues? Has anyone succeeded in running CP-V on those emulations?? It would be amazing to run CP-V and tha various languages on a Sigma 9 emulations, not to mention the 350-point and 550-point adventures.? However, I haven't found any type of software on line.? Does anyone know of a stash somewhere? I remember that the Living Computer Museum, when it was open, briefly had a Sigma 9 up and running with CP-V, but was restricting public accounts due to some issue with the account generation mechanism.? I wonder if someone associated with the Museum might potentially have access to some CP-V tapes or images, even if the museum is closed. Thanks in advance, Dave

4 years, 2 months

NEXT/LISP Mirror has viruses

by billdegnan＠gmail.com

http://mirror.informatimago.com/ This site has or had viruses at some point, the tigger files.html files are still present. be cautious, and let the person who runs it know if they're known. BIll

4 years, 2 months

mirror of ftp://unix.hensa.ac.uk

by spectre＠floodgap.com

Looking for some tools (guide_reader, others) that were apparently only on unix.hensa.ac.uk's FTP. This hostname still exists, but directs to University of Kent's mirror service, and there is no trace of the old archive. Anybody happen to have saved any pieces of it? -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com -- In memory of Peter Graves --------------------------------------------------

4 years, 2 months

IBM Model C typewriter

by van.snyder＠sbcglobal.net

I have an old IBM Model C typewriter. I can't bear to throw it away, even though it doesn't work well. The carriage doesn't advance, and the A key doesn't work. Do you know how to tune it up? If you want it, it's yours for the price of shipping. I'll probably take it to UPS and ask them to pack it. It will fit in a 24" x 18" x 12" box. Gross shipped weight about 40 lbs. Local pickup free. La Crescenta, CA

4 years, 2 months

PDP-11/34 FP11-A on eBait

by jnc＠mercury.lcs.mit.edu

Speaking of FP11-A's: https://www.ebay.com/itm/275096265379 I wouldn't mind having one, but not for that much! I wonder how much it will go for? Noel

4 years, 2 months

H7821 power supply in MicroVAX 3100, SCSI disk enclosures and others

by cctalk＠beyondthepale.ie

The recent discussion on BSC protocol prompted me to dig out my Microvax 3100 with DSH32 synchronous serial interface. It had been idle in storage for several years and it wouldn't power up, only giving a brief flash on the diagnostic LEDs and a quick twitch of the fans. There was a slight smell, like the stale air that comes out of a deflating tyre. I took out the H7821 power supply and found that five identical brown 1800uF 25V electrolytic capacitors on the output side had leaked. The SCSI disk enclosure where the machine's system disk lives required several power cycles to get it to run at all and it died as soon as the disk tried to spin up. It turned out to also contain a H7821 power supply which had a similar issue with the same five brown capacitors, although not as extensive as in the main unit. I found a second disk enclosure which had seen little use and grabbed the power supply out of that to put in the MicroVAX. It worked well enough to test with but there was a ring of goo around the bottom of one of the brown capacitors which was worst affected in the other units. Time to order a batch of replacement capacitors and figure out what else has been damaged. While it is not the worst I have seen, access to these power supplies for repairs is quite difficult and it is really difficult to debug them safely while they are running with the cover off :-( If anyone has anything with H7821 power supplies in them, I suggest checking on these capacitors. If anything with these power supplies is in storage, I suggest ensuring it is stored the normal way up as this should limit the ability of the goo to escape and spread around the power supply. And there I was thought I was being safe enough by removing the nicad battery packs some years ago... Regards, Peter Coghlan.

4 years, 2 months

The Portable C Compiler (pcc)

by ccth6600＠gmail.com

The original "Portable C Compiler" by S. C. Johnson (also known as "pcc") had functional support for the Data General Nova. Could somebody please point me to this original implementation? There is a modern C99 version of this compiler maintained by Anders Magnusson at: http://pcc.ludd.ltu.se/ Unfortunately in this version the Nova architecture is no longer supported and won't build correctly although associated files are still in the source hierarchy. I am looking for the original implementation - not any recent work. Thanks Tom

4 years, 2 months

8" Floppy Drives needed

by jnc＠mercury.lcs.mit.edu

> On Wed, Jan 12, 2022 at 12:16 PM Mike Katz wrote: > I am looking to make a RX01 (and hopefully RX02) disk formatter Something that can format floppies for the RX01 can effectively format RX02 floppies, too. An RX02 drive can convert RX01-formatted floppies to RX02-formatted floppies. Given how arcane the RX02 format is (sector _headers_ are written in single density; sector _data_ is written in double) I'd be pretty surprised if anything except an RX02 can do it. Noel

4 years, 2 months

PDF of FP11-A FMPS available

by jnc＠mercury.lcs.mit.edu

Just ran across this: http://wwcm.synology.me/pdf/MP00189%20FP11-A%20Field%20Maintenance%20Print%… which isn't available online in this form. (This appears to be a different scan >from the one on the Maine Coon site, split up into several TIFF's, as it has the cover which that one doesn't show.) As always, history shows that the best way not to lose things is to have multiple independent copies! So download often! Noel

4 years, 2 months

OT: looking for help remembering name/info about security bug

by sieler＠allegro.com

I've received a couple of suggestions, thanks, but none seem right. BTW, I'm sorry (Liam) that I didn't make it clearer that it was absolutely a software bug, which excludes Spectre, Rowhammer, Meltdown. Aside: the Meltdown and/or Spectre patch to macOS hurt performance ... the elapsed time to compile 500 programs increased by about 12%. (At the time of the patch, I tested (properly) before and after the patch ... then forgot to publish, and since misplaced my notes.) Although I mentioned 'code', I should have been more specific: C (or, possibly, C++), but definitely no other language. I don't recall it being a buffer overflow. I *think* it was some kind of authentication failure (e.g., incorrectly reporting "ok"), but I'm not sure. I do know I wrote a several page article about it, and how certain coding practices led to it, but I can't *find* the article now :( (not published) My guess of 4-6 years ago is possibly narrower than it should be, but I'm not sure. My hope is that by being reminded of the vulnerability name, I can search my computer, and backups, for text files containing that name :) (Or the name of function associated with the problem.) thanks, Stan

4 years, 2 months

OT: looking for help remembering name/info about security bug

by sieler＠allegro.com

Hi, I'm trying to remember the name (and some information about) a past security bug, for an article. Somewhere between 4 and 6 years ago (I think), there was a fairly major security bug reported (probably in Linux, or in SSH code, but something widely used). IIRC, the bug was a single line that called a function (possibly along the lines of CredentialsCheck), and may have involved a bit-wise or (or and) instead of a logical one. It may have been that either the routine wasn't getting called when it should, or that the programmer misinterpreted what the return value meant. Ring any bells? thanks! Stan

4 years, 2 months

Plessy core memory

by jnc＠mercury.lcs.mit.edu

> an adapter cable to go from a 9-pin male (shell; female pins) to a > 15-pin female (shell; male pins) Sigh, shouldn't try to type when I'm this tired. Female 9-pin (to plug into the BA11-D) to male 15-pin (for the DD11-C/D to plug into). Noel

4 years, 2 months

Plessy core memory

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > I'm guessing that the DD11-F is significantly different from the DD11-B? I assume theat "DD11-F" is a typo; there is, AFAIK, no DD11-F, and a Web search revealeddidn't turn anything up. (There are DD11-CF and -CK backplanes, as well as -DF and -DK, but the -CF and -CK differ only in power harness length.) > the 11/24 used +12 on the +15 lines. No idea what was wrong with DEC The: https://gunkies.org/wiki/MS11-M_MOS_memory I'm guessing it used the parts that the IC vendors could provide. > Don't know what would happen if you plugged a RL11 or other hex height > card into one of those slots, probably blow everything up. Not sure. Per: https://gunkies.org/wiki/Modified_UNIBUS_Device#Pinout https://gunkies.org/wiki/Extended_UNIBUS#Pinout These are _some_ of the MUD/EUB pin clashes: Pin EUB MUD AN1 - A21 - Parity P1 AP1 - A20 - Parity P0 BE1 - A19 - Internal SSYN BE2 - A18 - Parity Detect I don't think those would harm anything. Not sure about power pins - and have no incentive to research it, as I have no need/interest in trying it. > I know I ran it with two of these Plessy cards and a RX01 controller but > now that I look at it that would be impossible as both were hex cards Maybe Plessey designed them to go in a DD11-B? I know I've seen other third-party cards that would go in oddball slots. > and both could never fit in a 4 slot backplane with enough space for a > quad spc Why not? The two hexes in slots 2&3, the quad in 1 or 4. > a DA11-F Unibus window Wow; never heard of those. I'll have to do a CHWiki page for them. Luckily, the maint manual is online. There's also a DA11-B. > what would happen if I enabled the KT24 Unibus memory map..... All that does is allow DMA devices on the -11/24's UNIBUS access to the entire main memory: https://gunkies.org/wiki/PDP-11/24#System_bus_structure So if you hooked up an -11/10 to an -11/24 with a DA11-F, then with the UNIBUS Map on, the -11/10's CPU and/or DMA devices would have access to the entire EUB memory via the 24's UNIBUS Map, is all. > This is so much fun! That _is_ why we collect old computers! ;-) Noel

4 years, 2 months

Plessy core memory

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > the DD11-B is a MUD backplane No, it's SPC; other sources, e.g. http://www.chdickman.com/pdp11/Notes/DD11.shtml agree. So if you have a DD11-B, you must have a BA11-D, with the 9-pin power plugs. The best thing to do is get a DD11-C or -D, and build an adapter cable to go >from a 9-pin male (shell; female pins) to a 15-pin female (shell; male pins), so you don't have to mess with the harness. Part numbers here: https://gunkies.org/wiki/DEC_power_distribution_connectors Then you can plug in any memory you've got the right voltages for; the MS11-E takes + and -15V (in addition to +5V, of course). Noel

4 years, 2 months

Plessy core memory

by cz＠alembic.crystel.com

I'm working on my pdp11/10 getting it back together. One problem I think I have is that the secondary memory (a Plessy 700101-100) may be shorting the -15 line for some reason. Working on it, but does anyone have a manual or anything like that for this kind of memory board? Alternately, what kind of Unibus 16k memory board exists to get a 11/10 >from 16kw to 32kw of memory? Apparently I can't use a MM11-B as it requires +20 and -5, both of which are not provided by the power supply or sourced on a DD11-B backplane module. The 11/10 has +15, -15, and +5. On a related note, where did +20 come from for Unibus and which systems even supported it? Was it an 11/45,11/70 thing? Thoughts? C (Yes, I could build a regulator to take the 30 volts between +15 and -15 and create an independent 20 volts. Maybe. Likewise I could generate -5 >from the -15 and a 7815 regulator. Maybe.)

4 years, 2 months

Plessy core memory

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > the secondary memory (a Plessy 700101-100) may be shorting the -15 line > for some reason. Working on it, but does anyone have a manual or > anything like that for this kind of memory board? I've got a Plessey core memory manual somewhere, but I can't find it, so I don't know if it's the one you are looking for. I got it from Paul Birkel; it was a duplicate, and he scanned his and sent the scan off, but I don't think it made it online. > Alternately, what kind of Unibus 16k memory board exists to get a 11/10 > from 16kw to 32kw of memory? It all depends on what kind of -11/10 you have. If yours is in a 5-1/4" box, you can't plug a DEC memory card into the SPC slots that some of the CPU-holding backplane versions have because DEC memories (other than the ones like the MM11-L and -U, which are multi-board core systems that require custom backplanes) all require MUD slots, not SPC. All of the CPU backplanes on that machine are for a _specific_ kind of core memory (MM11-L or MM11-U), see here: https://gunkies.org/wiki/PDP-11/05 There are I think some third-party memories which can be used (Dataram, maybe?) but I don't have time to go into them. If you have a 10-1/2" box, you can mount a MUD backplane - but you might still have an issue because the older BA11-D boxes use the old 9-pin power connectors, and the MUD backplanes (DD11-C, -D, etc) all use the newer 15-pin ones. (Again, there are some oddball ones, and again, I don't have time to go into them.) If you're lucky enough to have one of the ones that will take a MUD backplane, an MS11-E/F/H/J: https://gunkies.org/wiki/MS11_32KB_MOS_memory would be an option. > On a related note, where did +20 come from for Unibus and which systems > even supported it? Was it an 11/45,11/70 thing? The later /05's, /40's and /45's were the first ones to provide +20V, for the then-new MM11-U. On machines which took H744 'brick's, the _later_ harnesses could take a H754 +20V, -5V regulator 'brick'. Alternatively, _some_ BA11-L's (used for the /04 and /34) had the right version of H777: https://gunkies.org/wiki/H777_Power_Supply to provide +20V. Noel

4 years, 2 months

The Portable C Compiler (pcc)

by jnc＠mercury.lcs.mit.edu

> From: Tom Hunter > The original "Portable C Compiler" by S. C. Johnson (also known as > "pcc") had functional support for the Data General Nova. Could somebody > please point me to this original implementation? > ... > I am looking for the original implementation - not any recent work. Of PCC, or the Nova version? The _oriinal_ PCC, released to the world in V7, is there: https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/mip https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/pcc https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/doc/porttour That one is dated 1979. I have a slightly later version, from 1982 or so, which is the 68K one done at MIT. Not sure if either of those is any use to you, though. Noel

4 years, 2 months

Mate-n-lok connector for H744 Regulator

by robert.jarratt＠ntlworld.com

To make testing of the H744 a bit easier I would like to try to make up some connectors for the mate-n-lok connector to make it easier to connect power and load. I know the H744 uses a mate-n-lok connector, but there seem to be a lot of different types and I don't seem to be able to find a type that would work. Does anyone know what the correct one is? Thanks Rob

4 years, 2 months

Mate-n-lok connector for H744 Regulator

by jnc＠mercury.lcs.mit.edu

> From: Rob Jarratt > Does anyone know what the correct one is? This: http://gunkies.org/wiki/DEC_standard_modular_regulators has all the details. (If anyone knows of any PDP-11 hardware or UNIX information which is not on the CHWiki - I'm not interested in DEC PDP-11 software, but if someone would like to take that on, that would be great - please let me know.) Noel

4 years, 2 months

Memory Tech you don't see very often

by pbirkel＠gmail.com

Selectron Vacuum Tube: https://www.ebay.com/itm/174977901251 Really nice photo-shoot! I wonder what the back-story to this particular tube might be. I don't think that $16.18 shipping would be, um, adequate protection by any measure. Cheap, but not so sure about "cost-effective" . -----

4 years, 2 months

What happened to Bill Whitson?

by s101885＠outlook.com

Bill Whitson, the original ClassicCmp ListOp, has a surprisingly little amount of information available about him online. Does anyone know what happened to him after the late 90s? (If anyone has any contact information, that would be nice!) Ryan Ottignon

4 years, 2 months

Source for replacement caps in H744 regulators

by billdegnan＠gmail.com

It would be a lot easier to replace the large circular regulator if you're taking the shotgun approach, and much more likely that the regulator is a source of faults. and it's cheaper. For the h744, 45, 54. BUT measuring things is the best way if you can do it. Pull the values from the backplane, there are test points that you can measure from. Bill On Thu, Jan 6, 2022 at 2:30 PM Wayne S via cctech <cctech at classiccmp.org> wrote: > So you want to replace capacitors just because they ?whine? ? > I?ll say that because you are learning, that is not good troubleshooting > practice. > Make a checklist of troubleshooting power supplies. > There are a lot of good youtube videos and other internet information on > how power supplies work, how to check them and repair them. There is danger > when working with power supplies. > When working on electrical equipment do you know about the ?working with > one hand in your pocket rule?? Doing this stuff, videos and reading, is not > overly time consuming and may save your life! > > > > Sent from my iPhone > > > On Jan 6, 2022, at 07:50, Jon Elson via cctalk <cctalk at classiccmp.org> > wrote: > > > > ?On 1/6/22 2:52 AM, Rob Jarratt via cctalk wrote: > >> 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. > >> > >> > > > > Mouser is a good place to find big caps (or at least used to be). You > might have to get "snap in" caps and solder wires to them, that style seems > to be more available. > > > > Jon > > >

4 years, 2 months

Memory Tech you don't see very often

by cclist＠sydex.com

On 1/6/22 10:17, William Donzelli wrote: > If you include prototypes, then you need to include ALL the prototypes > - even things made in single quantities that never worked. > > That is a HUGE amount of stuff that makes EBAM look gigantic. To be fair, EBAM received a not-insignificant amount of press coverage. What doomed it was the falling cost and increasing density of semiconductor memory. Good idea, wrong time. It was pitched in a few forward-looking responses to government RFPs. But then, so was a lot of other stuff. --Chuck

4 years, 2 months

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