test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

This: https://www.ebay.com/itm/275084268137 The starting price is expensive, but probably not utterly unreasonable, given that: - the 780 was the first VAX, and thus historically important - 780's are incredibly rare; this is the first one I recall seeing for sale in the classic computer era (versus several -11/70's, /40s, etc) - this one appears to be reasonably complete; no idea if all the key CPU boards are included, but it's things like the backplane, etc (all of which seem to be there) which would be completely impossible to find now - if any boards _are_ missing, there's at least the _hope_ that they can be located (780 boards seem to come by every so often on eBait), since people seem to keep boards, not realizing that without the other bits they are useless Anyway I fully expect it to go (because of those, especially i and ii) for a _lot_ more than the opening price. I've sent the seller info on the complete 780 board set, and a suggestion that it's in their own best interest (maximize bidding) to check to see if it's complete. Noel

4 years, 2 months

DEC HDD heads?

by anders.k.nelson＠gmail.com

Dunno if this is useful for anyone but the price seems right: https://www.ebay.com/itm/Qty-8-Cdc-Dec-Disk-Head-Heads-75010109-75010101-/2…

4 years, 2 months

3-phase power

by jnc＠mercury.lcs.mit.edu

> From: Scott Quinn > I have seen some roads where the utility has 2 of the phases plus > neutral going down them, not true 2-phase power, but 2 phases 120/240 > degrees apart with the third phase just not present. My street has that. The subdivision as a whole has all 3 phases (down the main road through it), but individual streets off of it have only 1 or 2. (The whole subdivision is on poles, so it's easy to see.) On the ones with 2, some houses are connected to one, some to the other. > I guess they figure twice the loads for only one more wire. No, because most homes are only connected to one phase. I think the main reason to do it is that it allows the total load (of the entire subdivision) to be somewhat balanced across all 3 phases. > Can't remember what it was called but I do remember seeing in some book > somewhere about a "phantom 3rd leg" or something My house has something like that; the previous owner wanted '3-phase service' for machine tools (I think - could have been a compressor, or something) in his basement workshop, so they sold him a pseudo-3-phase service. I forget the exact details of how it works, but the 3rd phase is at 170V to neutral, or something like that. (So I can't power any 110V outlets off the third phase.) I think the way it works is that the two 'main' phases are 220V to each other, 110V to neutral (I think from the usual center-tapped transformer off one of the three main feed phases, i.e. 180 degrees to each other). The third 'pase' is generated by a second, smaller transformer connected to the other feed phase in some arcane way I forget the details of. So it's 120 degrees away from the other two. Noel

4 years, 2 months

cctalk Digest, Vol 88, Issue 2

by compoobah＠gmail.com

On Sun, 2022-01-02 at 12:00 -0600, Grant wrote: > Where are you getting two /different/ phases?? --? Remember, the > different legs on residential 120/240 wiring are really the same > single > phase. > > How do you get *two* /different/ phases without access to a *third* > phase?? There are only a few places in the U.S.A. (and I'm not aware > of > anywhere else in the world) that actually have 2? power (where the ? > are > 90? out of phase with each other). I have seen some roads where the utility has 2 of the phases plus neutral going down them, not true 2-phase power, but 2 phases 120/240 degrees apart with the third phase just not present. Every time I've seen that it seems like fools economy, but I guess they figure twice the loads for only one more wire. Can't remember what it was called but I do remember seeing in some book somewhere about a "phantom 3rd leg" or something where they used 2 wires with 120/240 degree phase separation into the transformer and then the third phase "corner" was just floating and current would "return" across the other two. As it was brought up in the context of "make sure some yahoo didn't try this on your install and if they did be very careful" and was delta-only I imagine it was not that common.

4 years, 2 months

3-phase power

by jnc＠mercury.lcs.mit.edu

> From: Jon Elson > It should be 208V Oh, right you are. It's been a long time, and I had a distinct memory that it was less than that, but I looked, and I think that's it. The term for my flavour of 3-phase is apparently "open wye/open delta"; each leg is 240V to the others, but only two are 110V to neutral - the "hi leg" (normally colour-coded orange; normal 3-phase uses black/red/blue) is 208V. The page Jonathan Chapman sent had a good diagram of how it is wired: https://www.engineeringradio.us/blog/wp-content/uploads/2012/02/3-phase-ope… When they were doing some work on the pole decades back, I asked the foreman how it worked, and he drew a diagram to show me; I had forgotten it, but seeing that, that is it. The A and C are produced off one feed phase, but the B comes from the second feed phase. Noel

4 years, 2 months

11/785 on ebay (2018) - was Re: VAX 780 on eBay

by michael.99.thompson＠gmail.com

> > > Date: Mon, 3 Jan 2022 11:39:01 -0500 > From: Chris Zach <cz at alembic.crystel.com> > > The thing that always made me wonder is where are all the 8600's. The > 8600 was apparently the best selling large Vax, outselling the 780 and > 750, so what happened to all of them? They weren't any bigger than a 780... > > C > There is an 8650 at the RICM. https://www.ricomputermuseum.org/collections-gallery/equipment/dec-vax-8650 -- Michael Thompson

4 years, 2 months

RSTS V10.1 patch

by paulkoning＠comcast.net

I just added a patch to https://github.com/pkoning2/decstuff, in patches/shut.cmd, which cures a problem in RSTS V10.1 that seems to come and go with no clear pattern. The failure is a crash, sometimes a halt, during system shutdown. The cause was a write to the wrong location when removing the DCL runtime system, because of a register not being set before that action. The patch can be installed with ONLPAT; it takes effect immediately (because it patches a non-resident overlay). paul

4 years, 2 months

StorageTek 9-trk Tape Drive 2925 Restauration

by info＠schroeder-edv.de

Hello, Has anybody a? STC 2925 9-trk Tape Drive. I need a BIN- or HEX-File from an EPROM on the CP--Card. It's the PROM #1 with the number 403936303. Best regards Lothar

4 years, 2 months

Applesauce FDC

by nospam212-cctalk＠yahoo.com

I've recently picked up a new Applesauce floppy disk controller and have been playing with attaching various different drive types and imaging different Apple II, Atari, TI and other floppy disks with it. So far I've mostly imaged unprotected disks and run them in various emulators just fine. I've since added a sync sensor to one of my older Disk II drives and started to make some flux images of protected disks. These too seem to run fine in the emulators I've tried. The documentation on the device is limited at the moment, particularly the software, and while it is slowly being updated I was wondering if anyone else here had any experience with the setup. Any hints, suggestions, best practices, "do this to get the best copy", etc, to pass along would be appreciated. For example I read you can try to recover borderline disks by having it do multiple passes of the bad sectors. I see how this is done on the Fast Image option and has helped a couple of times but don't see any way to do something similar via the Flux Image option. Does it not work/matter with those? Also I see sometimes it reports a file as bad if I do one image type but if I do the other it comes back as okay. So I tend to play with both when I can. There is a lot of options and functions in the Flux Image option that I just really don't know how it works or what to do with it so far that any info would be great. I know it can image non-Apple II disks as well and I've done a few. It works great on Apple II protected disks but wonder how to deal with protected disks from other systems? Or is that more an issue of other emulators and such not having something like the .woz format being used with the Apple II? I bought this for my Apple II collection and it was a nice surprise to learn it could work with other systems too, just looking for more info about them as well. So far I really love the device and it has been worth the long wait for new units to come back into production again. Especially as it is a new design that allows for attaching PC floppy drives now as well. I've noticed the doc on the site being updated, just hope that they can find time to update more, particularly in regards to the client software. Best, David Williams www.trailingedge.com (http://www.trailingedge.com)

4 years, 2 months

The Prolok Saga (Was: Applesauce FDC

by marvin＠west.net

Another thing Prolok did was produce a small 3 disk set of sample disks with the Prolok protection. Somewhere around here I still have a set of those disks. As I recall, a program was included on each disk to copy the program to be copy protected to the special disk.

4 years, 2 months

PDP-11/44 gas struts

by Flash688＠flying-disk.com

Earlier, I wrote: > 30-pound struts are not strong enough. They improved things a bit, > but it still takes a lot of effort to raise the box. I have ordered a > pair of 50-pound struts and will post an update when they arrive (next > week). The pair of 50-pound struts arrived today, and in my opinion they are just barely adequate. If I was trying for perfection, I would use the 60-pound ones, but they currently have a 6 to 7 week lead time. I can easily live with these. In summary, what I have learned about replacement gas struts for the DEC PDP-11/44 in a 40" high cabinet: 1. The specifications are: 15.24" extended, 9.77" compressed, stroke length 5.47", threaded ball studs, extension force 50 or 60 (preferred) pounds. 2. A good replacement is the McMaster-Carr 4138T55 gas strut in either the 50 or 60 pound force version. The price as of January 2022 is $20.29 each. <https://www.mcmaster.com/catalog/127/1377> 3. The threaded ball ends on the 4138T55 are 5/16"-18 threads, while the original DEC ones are 5/16"-24. They are easy to swap without unscrewing them from the cabinet, and this is the method that DEC recommends and describes on pages 5-5 to 5-7 of the PDP-11/44 System User's Guide, EK-11044-UG. You simply unsnap a retaining clip (no tool needed), pop the strut off the ball end (a screwdriver might help), and reverse the process with the new strut. A piece of 4"x4" lumber does a good job of holding the box up while doing this (stick it under the rear of the cabinet when it is in the raised position). EK-11044-UG is available at: <www.bitsavers.org/pdf/dec/pdp11/1144/1144_UsersGuide.pdf>. (In my earlier posting I gave the wrong DEC P/N for the manual.) 4. The 4138T55 struts that McMaster-Carr sells are manufactured by Suspa Parts <https://www.suspaparts.com/>. The 30-pounds struts are their part number C16-24186, and the 50-pound struts are C16-24188. I suspect that the P/N for the 60-pound struts would be C16-24189, but cannot confirm that. Their price is $32.00 each, so it is less expensive to buy them from McMaster. 5. Suspa's design guide recommends mounting the struts with the rod end down, the opposite of how DEC mounted them. I have verified that they can easily be mounted with the rod down as long as you connect the upper (body) end first. That is the way I have them now in my system. I hope that this helps someone who might need to replace the gas struts on their PDP-11/44 system or something similar. It has been an interesting learning experience. Alan Frisbie

4 years, 2 months

11/785 on ebay (2018) - was Re: VAX 780 on eBay

by jnc＠mercury.lcs.mit.edu

> From: Grant Taylor > From that last picture, it looks like one of the plugs is five pronged, > and looks very similar to the 120/208V 30A 3? plug in one of the > pictures about the current 780 auction. Not too surprising; the /780 and /785 are basically the same machine. (In fact, one could convert a /780 to a /785 by pulling out the /780 CPU cards and replacing them with a set of /785 cards; basically the same cards, with the 74S chips replaced with 74AS.) Noel

4 years, 2 months

Apple I auction

by shumaker＠att.net

Another Apple I on the auction block: https://www.liveauctioneers.com/item/114629733_the-chaffey-college-apple-1-… Steve

4 years, 2 months

DEC RF30 Integrated Storage Element Service Guide

by robert.jarratt＠ntlworld.com

I am looking for the service guide for the RF30 DSSI disk. It is not on Manx and not on BitSavers. Does anyone know of a copy? The part number is apparently EK-RF30D-SV. Thanks Rob

4 years, 2 months

What is a BC01-R

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach >> Anyone know what an M857 is? I guess it might be a DF11 async answer >> mode? > No, it's a single width full height M series board from the early > 1970's. Argh, digit swappping on my part. The _M587_ is in the DN87 FMPS: http://www.bitsavers.org/pdf/dec/pdp10/periph/MP00068_DN87_Universal_Comm_S… (pg. 98); it's a dual-width card, an "Async answer modem" (the DF11-BB). The BC01-R cable is in there (pg. 89), but I don't see the M857. (Web searches don't turn it up either.) Noel

4 years, 3 months

What is a BC01-R

by cz＠alembic.crystel.com

Quick question: I'm going through my old cables looking for the paddle interface for the Current loop for my pdp8/L. I thought I saved one from my old pdp8/I, maybe not. Regardless, I found a M857 board with a RS232 cable on it and BC01R-25 on it. Was that for a pdp11/05 by chance? Oddly enough I also found the interface adapter that goes into my VT52 to support 20ma current loop devices. I currently use the VT52 as an RS232 console for my pdp11, but still, Wow.

4 years, 3 months

VAX 780 on eBay

by jnc＠mercury.lcs.mit.edu

> From: Jonathan Chapman > Last one that went auction-style on eBay went for $1,178.00 When was that? Do you have any details of the machine's config? That's a pretty good deal for a 780 (IMO). Noel

4 years, 3 months

What is a BC01-R

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > a M857 board with a RS232 cable on it and BC01R-25 on it. Anyone know what an M857 is? I guess it might be a DF11 async answer mode? I found this: https://www.computerhistory.org/collections/catalog/102731577 but I think the number there is wrong; I'm not sure exactly which KL10 board is an 'MBOX Control 3' - it might be the M9537. > From:Ethan Dicks > Sounds like it was a generic cable that probably worked with several > devices. Yeah, the BC01-R was used with an M957/M970 header card (not sure what the difference between them is) in the DF11: https://gunkies.org/wiki/DF11_Communications_Line_Adapter Not sure where else. Noel

4 years, 3 months

VAX 780 on eBay

by guykd＠optusnet.com.au

At 07:50 PM 1/01/2022 +0000, you wrote: >> >True. But if you're trying to get > $5000 for something, it doesn't seem unreasonable to suggest that investing a bit in getting an extension cord run to the location of the machine would be a good idea. The absence of that effort makes me wonder if the owner knows what the outcome of such a test would be and doesn't want to have to report it. >> > >But what would that accomplish? I think testing something like this requires a lot more effort than plugging it in and hitting the circuit breaker. To test this to see if some ODT comes up probably requires quite a lot of effort (locate a terminal/pc, wire it up, figure out where to plug it into the 780, etc. If this guy is a bulk dealer I would be surprised if he has the knowledge to do anything more than a power test which, again, would not be very useful and could even be detrimental. Exactly. The machine has a 3-phase 208/240V plug, they don't have such an outlet. Their efforts stop right there. But you're all focussed on that, and missing another important detail. The machine has a liquid cooling system. Some of the hoses look like they are Tygon, in the age-decayed brittle stage. Touch them and they crumble away. Running the machine without cooling would utterly wreck it. Even if they solved the mains power problem, they would be very unwise to actually power it up. The 'installation and configuration' manual for this machine would be huge. They don't have it. Plus, it's a mainframe. Not even any blinkenlights. Without setting it up as a complete system with everything interconnected properly, how would you even know it was running correctly? Plus you can safely assume at least some of the system unit interconnect cables are missing. Potentially weeks, even months of restoration work for a buyer, before even daring to apply power. Then if there's anything wrong in the electronics, good luck diagnosing and getting spare parts. Considering the uncertainties plus high transport, restoration, operating and manhour costs, who'd buy it? A museum perhaps? Or someone wanting a 'static display object' never intending to run it. Guy

4 years, 3 months

PDP-11/44 gas struts

by Flash688＠flying-disk.com

Chris Zach <cz at alembic.crystel.com> wrote: > Jesus. How much does the 11/44 chassis weigh? > > On 12/30/2021 3:39 PM, Alan Frisbie via cctalk wrote: > >> 2. 30-pound struts are not strong enough.? They improved things a bit, >> but it still takes a lot of effort to raise the box.? I have ordered a >> pair of 50-pound struts and will post an update when they arrive (next >> week). The box itself weighs about 75 pounds, plus the weight of the cards. Remember, however, that the struts are not doing a simple lift of the box. The box is acting as a lever. The box is 24" long, and the struts are only about 5" from the pivot. Also, the struts are not doing a straight lift from directly below their attachment to the box, but at a point about 11" forward from where they are attached to the box. All of this greatly magnifies the force required to tilt the box up. Anyone care to do the math on this? Alan Frisbie

4 years, 3 months

Testing a H744 Regulator on The Bench

by robert.jarratt＠ntlworld.com

Hello All, Following a discussion on resurrecting a PDP 11/45 I have started looking at the regulator bricks in the PSU. I have started with a H744. I reformed the three big capacitors, although they seemed to be fine as they charged up >from my DC bench PSU and then had zero leakage so I didn't reform them for very long. I then moved on to powering the whole unit from my DC bench PSU and it seemed to run fine. I am using a panel mount 1R resistor, so drawing 5A of the rated 25A. It drew just under 2A from the PSU which was set at 20V. I didn't run it for very long as I wasn't sure how hot to allow the load to get. Is there any sense in measuring ripple when powering this from DC? There does seem to be some ripple: https://rjarratt.files.wordpress.com/2021/12/h744-ripple.png hard to say if that is OK? Also, the indicator light does not work (as expected). I have seen the suggestion to replace it with a CM7381. It looks like these can be sourced <https://www.mouser.co.uk/ProductDetail/?qs=N8%2Bk0S5zvCZ7dMEMH2XU9Q%3D%3D> with relative ease, but I wondered if there might be a better LED-based longer term solution? I was also advised that OL-6003BP is good for the 15V regulators, but these seem to be hard to find, any suggestions there? Thanks Rob

4 years, 3 months

PDP-11/44 gas struts

by Flash688＠flying-disk.com

Mark J. Blair <nf6x at nf6x.net> wrote: > When I need gas struts and cannot identify a source for exact original > replacements, I usually look at McMaster-Carr first: > https://www.mcmaster.com/gas-struts/ Thanks for the McMaster-Carr suggestion, I should have thought of that. I removed the gas struts from my PDP-11/44 and found the following markings: Gas Spring Corp. Colmar, PA 1216166-0-0 22/81/3 (the "1" might be an "I") I measured them, and found a compressed length of about 9.8" and an extended length of 15.25". The threaded studs are 5/16"-24. I can't find the company, and Google turns up nothing with either of the number strings. Nor do the numbers seem to indicate what the specifications might be. Perhaps someone with better Google skills than I have might find something. It is, however, an almost perfect match for McMaster-Carr P/N 4138T55. The big unknown is the extension force. After cleaning and oiling them, one of the bad ones measures about 12 pounds, and the other is about 23 pounds. The 4138T55 is available in 15, 20, 30, 40, 50, 60, 90, and 120 pounds. I made a wild random guess and ordered two of the 30 pound struts, which should be delivered Wednesday (12/29/2021). The 40 pound ones have a seven week lead time, and a pair of 50 pound ones seem way too high. When they arrive, I'll let you know how well they work. Worst case, I will have wasted $20.29 each, plus shipping, and have to wait seven weeks for the 40 pound units, or go whole hog and try the 50 pound ones. Thanks for the help and suggestions. Alan Frisbie

4 years, 3 months

New mailadress

by pontus＠Update.UU.SE

Hi I've been using this adress for many years: "pontus at update.uu.se". But the club is now at risk of loosing the domain name. I'm therefore moving over to "pontus at dfupdate.se" Sorry if this is of topic but I have made many acquaintances on this list that might not find out otherwise. Regards, Pontus.

4 years, 3 months

New mailadress

by pontus＠Update.UU.SE

4 years, 3 months

86-DOS and Seattle Computer Products

by s101885＠outlook.com

Hi ccTalk! My name is Ryan and I may have been in contact with a few of you already (Rich, most notably) about this topic. I am on a pretty wide search of any versions of 86-DOS, or any information regarding it. As of now, I have 7 copies of 86-DOS. They cover a disappointing range of versions ? from 1.00 to 1.14. There are a lot of duplicates. Versions prior to 1.00 were sold ? for example, I know of 2 collectors with versions in the 0.3x range, but both are unable to image it due to technical limitations. I?ve already contacted quite a few people. Most interestingly are 5 former Seattle Computer Products employees, as well as 2 family members of SCP owner Rod Brock. Tim Paterson, the creator of 86-DOS, didn?t have a copy, nor its source code. Pat Opalka, who contributed a bug fix, is in possession of a few copies, though none are prior to 1.00 (he may or may not be able to image them ? if he does, I?ll send another message here). 3 other employees didn?t have any documents from the time, nor any copies of the software. The 2 family members of Rod Brock don?t have any copies, but have relevant documents and recordings that they are in the process of sending over. So, if you have any copies of 86-DOS, even if you don?t want to share or its version is 1.00 or above, please send an e-mail back. I can send over imaging instructions. It was sold with the following computers: - Seattle Computer Products 8086 System - Seattle Computer Products Gazelle - Lomas Data Products LDP88 - Lomas Data Products LDP1 - Lomas Data Products LDP2 There are 8? copies for Tarbell and Cromemco floppy disk controllers, as well as 5.25? copies for NorthStar disk controllers. I will also take other relevant things such as people to contact, manuals, recollections of versions you may have had, etc. Thank you all for your time! - Ryan Ottignon

4 years, 3 months

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