test-drb August 2020

test-drb@ccmp.vtda.org

116 participants
97 discussions

by a.carlini＠ntlworld.com

I have three AlphaServer 2100 systems in storage in the UK (Oxfordshire). The storage, however, is due to be demolished (soon, but no fixed date). I won't have room to store these three systems, so if anyone would be interested in offering them a home, then please get in touch! I can probably get some pictures in the next day or two. These systems were SMP Alphas and could sport as many as 4 CPUs. I'm not sure of the configuration of these systems but I can probably find that out soon. They have not been run since ~2003 so they may be in need of some TLC. OTOH they are not rusted to death so you have a chance of getting them back to life. Just so you know what you might be dealing with these systems are about: 700mm H x 430mm W x 810mm L. I can't find the weight in any of my references right now but they are very heavy. Three people can move them up a slight slope with some effort but you would not successfully lift it into a car (assuming that it would fit). I'm planning to dismantle them to move them (i.e. remove PSU/PSUs etc. until they are light enough to move). A tail-lift would probably be the sane way to go (and is, indeed, how they got to their current location. I'm hoping that someone can step forward and offer one or more of these machines a new home. Please contact me off-list (once you're sure you understand what you are getting into :-)). Antonio -- Antonio Carlini antonio at acarlini.com

2 years, 6 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.

2 years, 8 months

PDP-11/05 microcode dump?

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > Thanks Noel for sorting this out. Eh, de nada. But thank you. >> I wonder if the ucode in the two versions is identical? The uROM chip >> numbers should give it, (if they are the same on both versions, albeit >> in different locations on the board), but I have yet to check. Does >> anyone happen to know? OK, so the situation here is pretty complicated. To start with / make things worse, that CPU uses lots of PROMs. Lots and lots and lots and lots of PROMs. For the data paths board (M7260), both major versions appear to contain the same PROMs (going by the DEC part numbers), but the chip location (Exx) numbers are all different. For the control board (M7261), the C, E ('early' version) and F ('late' version) etch revisions each contain mostly the same PROMs, but apparently with slight differences between the sets of PROMs in each (as reflected in different DEC part numbers). For details see: http://gunkies.org/wiki/PDP-11/05#Control_PROMs to which I have just added all the gory details. As to getting the contents of all of them dumped in machine-readable form - oi vey! >> on the earlier version (prints for that version are in the GT40 prints >> online It turns out that I have hard-copy prints for the "C" etch revision of the M7261, which do not yet appear to be online; the GT40 prints have the "E" etch revision. I will scan the pages for that revision of the board, and put them up 'soon'. (I'm not doing the whole print set, it's about 1" thick, and most of them are for other things anyway, like MM11-L memory, etc.) Noel

3 years, 3 months

Apple IIe case screws

by mokuba＠gmail.com

Does anyone know the size/threading of these? I've been searching high and low and haven't been able to find any approximate or otherwise specs (they use captive clips, so close is OK) - i've found the PSU mounting screw sizes and sourced those though. -- Gary G. Sparkes Jr. KB3HAG

3 years, 10 months

ISO earl TI DSP kits

by aek＠bitsavers.org

CHM doesn't seem to have much early DSP stuff in the collection Does anyone have any of the TMS32010/20/30 or C1x/2x/3x hw/sw kicking around? Other than the docs I've scanned there doesn't seem to be much on the web either.

3 years, 10 months

Font for DEC indicator panels

by jnc＠mercury.lcs.mit.edu

> From: Toby Thain > To get closer I'd need better images of the panels. Hi, I borrowed a DEC inlay from someone (a KA10 CPU bay) and scanned a chunk of it (as much as I could fit into my A4 scanner :-) at 200 dpi: http://ana-3.lcs.mit.edu/~jnc/tech/jpg/KACPUPanel.jpg I have a TC08 inlay, but it's currently being used in my QSIC display (until we can get the RKV11-F/RPV11-D inlay done :-), and I didn't want to yank it out. As far as I can tell, it's the same font on the two of them. > the closest I know of off the top of my head is Akzidenz Grotesk. The Akzidenz Grotesk Medium is indeed very, very close (other than the zero). Do you happen to know if that font available for use in non-commercial settings? Thanks! Noel

3 years, 11 months

Pro 350 Print Set

by robert.jarratt＠ntlworld.com

Manx lists MP-01394-00 as the Field Maintenance Print Set for the DEC Professional 350. I can't find this online and I was wondering if anyone has a scan of it by any chance? Thanks Rob

4 years

Sun SPARCstation LX boot from CDROM?

by ccth6600＠gmail.com

About 20 years ago I rescued a fully working Sun SPARCstation LX with CDROM and QIC-150 tape drive - all 3 in lunchbox format - plus monitor when we moved office and management decided they no longer wanted/needed it. Shortly after I have installed an early version of NetBSD (1.3.3) from the CDROM drive. I played with it for a few days and then stored the entire system in a museum grade glass display cabinet. This is indoors with minimal dust and benign temperatures between 18 degrees C to about 28 degrees C (typical room temperatures here in Perth in Western Australia unless you run the air conditioner). Now retired I took the stack of "lunch-boxes" and the CRT monitor out of the display cabinet and powered it up. After 20 years no smoke came out but the system didn't boot but reported trouble with the NVRAM setting. I still could start NetBSD using a "boot disk" command. I googled the problem and bought and installed a replacement TIMEKEEPER chip (M48T08-100). After defaulting the settings and setting the MAC address and machine ID it was happy and booted from disk without intervention. In NetBSD I then set the date and time and all was good. Then I decided to upgrade to the latest version of the SPARC version of NetBSD 9.0. I downloaded and burned the ISO image to CD. Dropped it into a CD caddy and inserted it into the CDROM drive (SUN Model 411 - really a Sony CDU-8012 3.1e). I did a "probe-scsi-all" and it found both the hard drive and the CDROM (target 6 unit 0). Now comes the problem - if it try to run from it via "boot cdrom" it doesn't even access the CDROM drive - the LED doesn't turn on unlike when you do the "probe-scsi-all". The "cdrom" alias is really: "/iommu/sbus/espdma at 4,8400000/esp at 4 ,8800000/sd at 6,0:d". The "disk" alias is really: "/iommu/sbus/espdma at 4,8400000/esp at 4,8800000/sd at 3,0" The "@3" versus the "@6" are the SCSI IDs of the disk drive versus the CDROM. I don't know what the trailing bits mean. I tried cdrom aliases from "sd at 6,0:0" to "sd at 6,0:f" and all report: Can't read disk label Can't open disk label package Can't open boot device The LED doesn't blink even once unless I remove and re-insert the caddy with the CDROM media or if I do a "probe-scsi" or "probe-scsi-all". I tried original Sun Solaris 2.4 installation media with the exact same result/symptoms. I also tried to access the CDROM from NetBSD using "cat /dev/cd0a" but the drive's LED didn't blink and I got an obscure error message. The Boot ROM revision is reported as 2.9. The system was bought about 1985 or 1986 and has seen very little use. I searched google without success. Maybe I used the wrong search terms or the equipment is just getting too old and FAQs have disappeared. What would cause the CDROM boot problem? There is a chance that the actual Sony drive died. I partially disassembled it hoping to find dust stuck on the LASER optics but it was nice and clean. The positioning and ejection mechanisms work just fine. The whole system was working before I put it into my relatively dust proof glass display cabinet. Thanks and best regards Tom Hunter

4 years

Brittle plastic

by ccth6600＠gmail.com

Today I was working on a very nice 1995 vintage SPARCstation LX with CDROM and QIC-150 tape drive (3 lunchbox type units). I was trying to install a newer version of NetBSD on it than was already installed. The stack of 3 units was stored in a museum grade glass display cabinet. Sadly all 3 units have a small degree of yellowing but more importantly the plastic cases have become very brittle and bits just break off with minimal mechanical strain. Is there any process to reverse the brittleness which could be used to preserve the cases? Thanks Tom Hunter

4 years, 1 month

IBM 3270 compatible terminal connected to Hercules IBM mainframe emulator.

by mattislind＠gmail.com

I have been working on a project for some time to connect a IBM3270 compatible Alfaskop terminal with its IBM 3274 compatible cluster controller to the Hercules mainframe emulator. Yesterday I eventually succeeded. I was able to login to TSO on my Hercules system that ran MVS 3.8j. Here are a couple quick video clips: https://youtu.be/H1Sxt7xjn4Y https://youtu.be/CFfB3yCN9OI To achieve this I created a small piece of hardware I called SyncDongle, essentially it's just a few level converters, connectors and a STM32F103 blue pill. On the hardware I run a small piece of firmware, BSCBridge. It bridges between the sync serial BSC used by the Alfaskop cluster controller and the BSC variant that the 2703 emulation inside Hercules is using. More information here: https://github.com/MattisLind/alfaskop_emu and here http://www.datormuseum.se/peripherals/terminals/alfaskop There are good chances that the SyncDongle/BSCBridge combo could work with a 3274 or 3174 controller as well but I haven't tested since I don't have one. But no guarantees given, though. If someone has a spare 3174-51R, -61R, -81R or -91R I would be very interested in it. Actually there is a good chance that it could work with general BSC use. Maybe for NJE between Hercules and a real IBM machine? Or 2780/3780 RJE terminals? Or other third party 3270 terminals using BSC. The BSCBridge firmware only supports non transparent mode at this point, it works fine with Alfaskop since it does not support anything else. Maybe a showstopper for 3174 with 3279 terminals? SHouldn't be that difficult to add transparent mode if needed. /Mattis

4 years, 1 month

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test-drb August 2020