test-drb

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101090 discussions

Upgrading BA11-N to BA11-S (was: Unibus/qbus wire wrap tool)

by jnc＠mercury.lcs.mit.edu

Thanks to everyone who responded. (And for the pointer to the BA11-N prints; I had that print set, just hadn't look all the way through it! Although I still hope a copy of the Tech Manual shows up some day.) > From: Pete Turnbull > For each BDAL line I used a suitable length of wire-wrap wire to run > the length of the bus plus an allowance to wind once round each pin. I > stripped somewhat over an inch of of insulation from the end, then used > the stripper to separate the remaining insulation everywhere it would > solder to a pin. Soldered one end, wind once round every succeeding > pin, and soldered each. Thanks for that tip - I had been planning on using separate lengths, but one piece made a lot more sense. (Although I used wire from a 25-pair telephone cable - I like working with that, it takes solder very easily, which not all wire wrap wire will.) Noel

11 years, 10 months

Mayflower MFE 750/751 8 inch floppy drives

by malcolm＠avitech.com.au

Just wondering if anyone has (or can point me to) any technical information about Mayflower's MFE 750 and MFE 751 8 inch floppy drives. I have one of each of these drives, and am looking for information about the configurations settings etc. Regards, Malcolm.

11 years, 10 months

Upgrading BA11-N to BA11-S (was: Unibus/qbus wire wrap tool)

by malcolm＠avitech.com.au

> I have verified that the CD part of the backplane is identical in both (the > 1983-84 Microcomputer Interfaces Handbook, EB-23144-18, has pinouts for > the CD > part for both, and they are indeed identical). Alas, I cannot find detailed > data on the rest of the H9273-A: neither the BA11-N Technical Manual, nor > the > Print Set, is available online. (I found some old list email which > indicates > that someone named David Powell had a copy of the TM - does anyone know > him?) > > Noel > Hi Noel, there are H9273/H9273A PCB layouts and wiring diagrams at pages 41-51 of the "PDP11/23 Field Maintenance Print Set". A Google search for "MP00740_1123_schem_Oct81" will bring it up on Bitsavers. Malcolm

11 years, 10 months

Wanted: Vintage Texas Instruments Guru

by charles7＠slingshot.co.nz

Hi I am a model railroader (in HO scale) and use a digital controller from the 1980s. The controller is a Hornby UK, Zero 1. This device is based around the TMS1000NLP and has been excellent value over 30 years. The only small improvement I would like to make is to increase the number of locomotive addresses to above the current limit of 16. (because of4-bit chip). The TMS1000 has a masked program (MP0186) and the ram can be dumped in 2 ways, by removing physically the top of the chip and photographing etc. The second option is dumping code via the test mode, as mentioned in TI literature. I would like to be able to discuss with someone about instructions to use the Test Mode etc. Also I would like to locate a list of the TI TMS1000 programs MP**** (incl the MP0186 above) Dave Caroline was good enough to direct me to this mailing list. Thankyou Charles Harris NZ

11 years, 10 months

Further PDP-11/05 debugging -- core memory faults

by derschjo＠gmail.com

Hi all -- The CPU in the 11/05 seems to be behaving nicely as far as I can tell, now that the Microcode ROMs are no longer filled with bogus data. It will run small programs I've toggled in without issue, and so I've moved on to testing the memory. Basic testing (via the simple address test listed here: http://www.psych.usyd.edu.au/pdp-11/hints.html) reveals that most of the 8KW of core (H215) and controller is working pretty well, except for a 128 byte range between 012000(8) and 012200(8). Within this range, all words read back as all zeros regardless of what is written. Given the nature of the fault, I tend to think that this is not an addressing problem or an issue with the core drivers -- if it was any of these I'd expect the fault to repeat across the memory space in a pattern, rather than being isolated to a single contiguous block of memory. If that's true, then it seems that the core plane itself might be at fault. Which doesn't surprise me, I'm actually surprised it works at all -- when the /05 arrived the H215 core memory board was loose, banging around inside the chassis. Does my initial analysis seem reasonable? Anyone have any experience debugging one of these and have any tips to share? Thanks, Josh

11 years, 10 months

TD Systems Inc Viking QTO / QDO conversion. QBUS.

by mattislind＠gmail.com

On Thu Jun 19 10:28:44 CDT 2014, Zane Healy <healyzh at aracnet.com> wrote: >On Jun 19, 2014, at 8:14 AM, Glen Slick <glen.slick at gmail.com> wrote: > >> On Thu, Jun 19, 2014 at 7:53 AM, Zane Healy <healyzh at aracnet.com> wrote: >>> >>> Yes, yes, and yes. I did this 15+ years ago, you're making me feel old. :-( >>> >>> You need the following: >>> 1. A high enough version of the EPROM >>> 2. A PAL Fuse Map for burning a PAL that will allow the board to act as a QDT controller (Disk and Tape) >>> 3. A special cable that allows you to connect a Serial Terminal >>> 4. Instructions on how to get into the hidden menu to configure the board >>> >>> I should have #4, but I have no clue as to where it is. The person I knew that had #2 lost that data in a fire years ago. I seem to recall hearing about someone jury-rigging #3, I used the pr\ oper cable and bulkhead plate. >>> >> >> If you burned your own PAL yourself and you didn't secure the PAL (or >> does a PAL16L8 even have a security fuse?) then even if the known PAL >> Fuse Map was lost I would assume that it could just be read back from >> the PALs on the boards you have, along with dumping the firmware >> EPROMs as well. >> >> -Glen > >The person that burned the PAL's is the person that had the fire. > >Zane I have had some progress in this matter: I got a reply to the letter I sent to folks at tdsys.com. The gentleman had forwarded to the designer of the Viking series of adapter boards and to the lady that was working with configuration of products. He had not yet go a reply from them. I also checked how the address decoding PAL is connected and I now understand that it has two outputs, connected to another PAL chip and then 16 inputs. These 16 inputs are the 4 jumpers and also BDAL02-BDAL12 and also the BBS7 signal. Looks quite reasonable being an address decoding chip. I more or less presume that the reason for two outputs is that one is for disk and one is for tape. I have to verify that by reverse engineer the actual content of the PAL using a small arduino board. You mention that there is a special way of accessing the configuration menu. It make sense since when I examine the board more carefully I discover a small serial EEPROM that might be used for storing the configuration. It would be really interesting to get more info about how to access this secret menu! Anyone else out there that knows about this? I have the cab kit for it. It has a DB25 connector as well as a 50 pin male IDC connector. But there is also pads for a 10 pin connector that seems to be for the second serial port. What is the use for this second serial port? The board has a Signetics SCN2681 DUART chip so it definitely has two serial ports. Regarding versions of the firmware. My firmware is 4.0 : https://dl.dropboxusercontent.com/u/96935524/Datormusuem/Viking_Q_B_A4.0.bin Zane, Pontus: What is your version? Mattis Lind

11 years, 10 months

FYI - terms of "equipment available" emails

by jnc＠mercury.lcs.mit.edu

> From: Jay West > Ensure that if you ever no longer wish to keep the machine that it > winds up in the hands of another collector This all seems eminently reasonable, but I had one question/clarification, about the above: what about museums? In other collecting fields I am aware of (Asian art, old racing cars, steam locomotives) there are a range of opinions about giving things to museums. (I personally don't have any strong feelings / axes to grind either way on these issues, merely raise them as I know there is debate on them in other field.) One issue with museums is that a lot of their holdings are stored out of sight, never to be seen by the ordinary public, and in that case, they might as well be with a collector who can enjoy them, and show them. The other issue (only with the cars and locos) is that some museums have a strict 'conserve it exactly as it was' policy, and since these things were intended to be _used_, an old race car/loco that's been 'stuffed and mounted on a plinth' (as the phrase goes in loco preservation) is akin to a zoo full of stuffed and mounted animals. Yes, using them can cause them to wear out (although there are rare counter- examples - John Harrison's sea-going clocks H1 through H3 are allowed to run, as their bearings, etc are thought to have indefinite life-times - which is not the case with H4, his first chronometer, which is displayed stopped), and also, to get one running may require replacement of some parts (although one can always save the old parts, for historical purposes). Like I said, I can see both sides - just wondered what the feeling was about this. Noel

11 years, 10 months

Any info / software available for a Ridge 32/330?

by derschjo＠gmail.com

Hi all -- I have the opportunity to pick up a Ridge 32/330, which looks like a pretty interesting 32-bit server/workstation from the mid-80s. It looks seriously cool, but I'm a bit hesitant to jump on it since it's a pretty large machine (well, relatively speaking...) that I haven't been able to find much information about. I have a few *other* interesting machines that are basically doorstops due to lack of media and documentation, I'm not sure I need another to add to that category :). What say you, O Internet Collective? Thanks, Josh

11 years, 10 months

Upgrading BA11-N to BA11-S (was: Unibus/qbus wire wrap tool)

by jnc＠mercury.lcs.mit.edu

> From: David Riley > I think most if not all Qbus backplanes were PCBs. But some of them > (notably the H9270) are PCBs with wire-wrap posts for the connector > terminals. Makes it very handy to, say, modify the H9270 for 22-bit, > which I did .. with no problem. This reminds me of something I'm looking into. I have a BA11-N (Q18/CD) which I'd like to upgrade to BA11-S (Q22/CD). (Yes, yes, I know, the -S has a oomphier power supply, which I won't have, but I'm not trying to run a lot of power-hungry cards.) I've tried finding an H9276-A backplane (Q22/CD) to go in it, to replace its existing H9273-A (Q18/CD), but _every_ place I called which had one listed reasonably cheap (<$100), and which claimed their internal stock database (i.e. not just their lame, useless, Web-site) showed they had one... when they checked the actual shelf, they did not in fact have any. So now I'm thinking, maybe I'll just add the BDAL19-22 lines to the existing H9273-A. It doesn't have wirewrap pins, but there's enough pin showing that I can get two wires onto each pin, and solder them; does not look to be difficult at all. I have verified that the CD part of the backplane is identical in both (the 1983-84 Microcomputer Interfaces Handbook, EB-23144-18, has pinouts for the CD part for both, and they are indeed identical). Alas, I cannot find detailed data on the rest of the H9273-A: neither the BA11-N Technical Manual, nor the Print Set, is available online. (I found some old list email which indicates that someone named David Powell had a copy of the TM - does anyone know him?) So, has anyone tried to upgrade an H9273-A to H9276-A, and are there any pitfalls? From what I can see, there shouldn't be a problem, but I'd like to be 100% sure before I start plugging cards into it... Noel

11 years, 10 months

DECwriter Casters/Wheels

by silent700＠gmail.com

It was recently pointed out to me that my DECwriter II (LA36) has holes drilled on the bottom of the stand to accept pads or casters. Does anyone know the measurement and thread size of those holes? I'm willing to use DIY-store parts to make these beasts mobile. No DEC-original parts needed. The DECwriter III (LA120) also appears to have the same holes. Are they the same size as the LA36's? Worst case, they can go on furniture dollies, but I'd like to try doing it "right" first. TIA - jht

11 years, 10 months

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