test-drb June 2009

test-drb@ccmp.vtda.org

233 participants
404 discussions

by mcguire＠neurotica.com

On Sat, June 20, 2009 7:27 am, Christian Corti wrote: > On Fri, 19 Jun 2009, Mr Ian Primus wrote: >> Now, here's the dilemma. The stock card won't respond to the usual debug >> commands - they just freeze the computer. The original 20mb 3 1/2" > > Normal MFM controllers never come with an own BIOS, so there's nothing to > jump to. XT controllers do. But now I recall that Ian said "WD1003" and I seem to recall that that's the AT controller series. I think I remember using an "IBM Advancced Diagnostics" floppy, or something like that, for this. -Dave -- Dave McGuire Port Charlotte, FL

15 years, 6 months

MicroVAX II Diagnostics Config and Devices Display

by steve＠cosam.org

Robert Jarratt wrote: > I am trying to get my MicroVAX II working, and now, thanks to a generous > person on this list, I have a working CPU and Memory combination. I am now > trying to run the MicroVAX II diagnostics from the TK50 diagnostics tape > that came with the machine. The puzzling thing is that it does not seem to > display the correct configuration and devices when I select that option from > the menu. Here is what it says: ... > So, the question is, should I expect to see these devices listed, should I > expect it to tell me how much memory is installed? If I am not seeing the > devices listed and they are known to work, why would they not appear? I > suspect that the M7559 might not appear as it controls a TK70 and this > MicroVAX II probably predates that device. I'd expect to see total memory and a list of devices. Which backplane are you using and where are all the modules inserted? Have you tried moving them around to see if you at least get different results? Cheers, -- Steve Maddison http://www.cosam.org/

15 years, 6 months

Terak 8510/a monitors available - Seattle WA

by bear＠typewritten.org

There are two Terak monitors at Re*PC in Seattle. They are headed for the Tukwila store, where they may remain for a short time, but I can't say from there whether they'll go on the floor, on eBay or be scrapped. My contact mentioned he thought he'd seen the keyboards come through separately, earlier, but that if so they'd already been sent to Tukwila. This should be taken as apocryphal as they keyboards really could belong to anything. Crappy cel phone photos: http://www.typewritten.org/~bear/junk/IMG_0065.JPG http://www.typewritten.org/~bear/junk/IMG_0066.JPG If you're interested, move fast. I am willing to serve as an intermediary if necessary. ok bear

15 years, 6 months

MicroVAX II Diagnostics Config and Devices Display

by robert.jarratt＠ntlworld.com

I am trying to get my MicroVAX II working, and now, thanks to a generous person on this list, I have a working CPU and Memory combination. I am now trying to run the MicroVAX II diagnostics from the TK50 diagnostics tape that came with the machine. The puzzling thing is that it does not seem to display the correct configuration and devices when I select that option from the menu. Here is what it says: SYSTEM CONFIGURATION AND DEVICES SYSTEM CONFIGURATION CPUA ... MicroVAX CPU KA630-AA 1MB, FPU MC=00 HW=00 Press the RETURN key to return to the previous menu. > I have never used these diagnostics before so I don't know what should be displayed. However I also have in there the following devices: Two memory boards. M7559 - TK70 controller. Known to be working as that is what I booted the diagnostics from. M3106 - DZQ11 Asynchrnous Multiplxer (4 lines) M7555 - RQDX3 Disk Controller DEQNA - Known to be working as I can do partial network boots (fails for other reasons yet to be determined) So, the question is, should I expect to see these devices listed, should I expect it to tell me how much memory is installed? If I am not seeing the devices listed and they are known to work, why would they not appear? I suspect that the M7559 might not appear as it controls a TK70 and this MicroVAX II probably predates that device. I ran the diagnostic tests and it tested only the CPU, which passed the tests. Thanks Rob

15 years, 6 months

IBM 2740/2741 terminal

by wmaddox＠pacbell.net

Is anyone here interested in an IBM Selectric terminal? It is a 2740 or a 2741, but I'm not sure which. Please reply privately. --Bill

15 years, 6 months

Service Manual for Ball TV-90 monitor?

by derschjo＠mail.msu.edu

Decided to dig out my IBM 5120 and try to get its monitor working, at long last. It's a Ball TV-90. Anyone out there have the service manual for this? (Worst case, there's a copy on eBay right now, but before I go through that I thought I'd bug you guys...) I mentioned this issue a few years ago, here's a photo of the interesting distortion I'm getting: http://yahozna.dyndns.org/scratch/5120disp.jpg. Thus far I've done a complete cap kit with no effect. I hate working on monitors, but I really want to get this running again... Thanks, Josh

15 years, 6 months

Hardware Hobbyists vs. Emulator Enthusiasts vs Replica Recreators

by roger.holmes＠microspot.co.uk

On 18 Jun 2009, at 20:06, cctalk-request at classiccmp.org wrote: > > From: Ray Arachelian <ray at arachelian.com> > >> I now plan to publish my emulator on the web, along with original >> software which non programmers can run on it. I am very unsure of how >> many people will be interested in such a thing. I need to get the >> physical machine running to retrieve said software from unique ten >> track mag tapes and from standard 80 column cards, though I could >> probably get the latter read elsewhere, I don't want to have to >> transport about 150,000 card somewhere to have them read, probably at >> great cost. > Hey, I'd happily play with it. I probably won't get very deep into > it, > but I would like to interact with it and see what it was like. (Which > mainframe btw?) The ICT 1301 dating from 1962. It is possibly unique in not having a program counter. Of course there is a way to get the next pair of instructions or a double length instruction. If you think of it as a three instruction pipeline which (in normal operation) always contain an instruction to do the instruction fetch that gives you the idea. The fetch instruction is an absolute jump, so contains the address. After execution it re-enters the pipeline with one added. There can of course be more than one absolute jump in the pipeline, it can even be all jumps, and the jump instruction can be used to jump to a subroutine which saves some of the pipeline in memory as its first instruction. > Hopefully you'll add various things to make the experience more > authentic, such as sounds and pictures/animation of actual tapes, > punch > cards, etc. (As much as possible.) Yes that would be nice. > You've done a wonderful thing by letting people look inside a large > machine. Hopefully you'll get the chance to do it again and get to > see > lots of smiles on the little kiddies faces. Thanks. Not so much smiles as wide eyed amazement. >> For micro computers I agree, not quite sure this applies to >> mainframes. I guess it depends on how you define software. If a >> single >> instruction is software then I suppose so. At the lowest level >> debugging I can set an instruction into control register one, set the >> machine to single cycle and watch the lights on the console as I send >> single clock pulses through the hardware every time I press a button. > Sorry, that's still running software. Microcode is still software My machine has no microcode its all hard wired logic. Confusingly there are two instructions, the multiply and the block move which proceed in small steps in what the manuals micro instructions but there is no memory of any sort they are read from, no micro instruction set, just logic which decides if the multiplier, or word count has reached zero and if a (decimal) digit is more or less than five to decide to subtract or add the multiplier. > You can hold a programming class. Maybe provide actual documentation > ahead of time so they know what to expect and can have an idea of what > sort of programs that they can execute, maybe provide some samples for > them to start with and tweak as they go along. For ordinary visitors we don't have contact beforehand. We could possibly have days in the same way as preserved steam railways have days when they sell people the experience of being a steam engine driver, under strict supervision of course. Car racing tracks have days when you are taught the safety rules and the allowed to drive around the track in a fast car accompanied by a professional racing driver. This costs a lot of money of course. For computers maybe something could be done on the web for free with emulation. This could be worldwide all year around. Any local people could arrange to come and run their programs on the real hardware in the warmer months. > If you can get actual > terminals to the mainframe, once they're done using the emulator, you > could fire up the real thing and let them play with that for a short > time. Maybe if you're worried about the cost of the electricity, you > could charge a bit of cash for that purpose and let them know what the > cost is for. Forget terminals, the machine never had them. A very small number of them had the optional teleprinter but I have never seen one. I could hook up a teletype, Flexowriter or a Creed but there is no operating system to use it with. There are 400 words of protected drum storage to hold a punched card bootstrap and a few utilities. > I don't think several hundred visitors a day would write code, they > might just want to see it in action, but maybe a few dozen would > like to > get deeper. Maybe I could ask people this year if they would like to do that. Too soon for this year anyway, 12th July is too soon to do anything much. > Sure, there will be much better 3D modeling software out there by that > time, but I imagine many would want to go back and see what it was > like > in the day and experience that for themselves. Hmm, I suppose I am falling into the same trap as the people who scrapped the mainframes, assuming that because things are no longer useful they have no reason to exist. > Myself, I have two little ones, they're not quite old enough to > understand computers yet, though I've given them one to play with - > right now they just use it to watch videos or listen to kids' > audiobooks > on. Rarely they play games on them. But when they're about 9 or so I > imagine I can show them a lot more and let them play with the machines > I've collected over the years and maybe they can play with the ROM > BASIC > and code a bit. :-) Something I'm looking forward to. Yes, before they become teenagers and have no patience. >> One aspect of emulators I have not yet explored is, well hold on a >> second and I'll explain. When looking through the 1301's >> documentation, circuit diagrams and instruction set, I am very >> tempted >> to add improvement which could have been done by the designer, but >> for >> some reason, either budgetary or lack of knowledge (some software >> techniques had not been invented yet). In an emulator I could add >> indexing or indirect addressing, or immediate mode data, or relative >> mode, or branch on NOT some condition without having to modify the >> actual hardware. I could then try programming the machine in that >> configuration and see how it affected the program size and ease of >> programming. >> >> It would be even more fun if the emulator was done at logic gate >> level >> and even more so if mated to an interactive 3D model of the hardware >> where you could open the cover, insert emulated scope probes and look >> at the signals. You could even emulate random logic failures for >> educational reasons, though to do so as a game would probably be a >> step too far for me, though programming the emulator to do it WOULD >> be >> fun. > Right, a logic simulator could be used to model this, and later you > could change the emulator around to match the proposed change. Gate > level emulation is very difficult. Not so much difficult to write, > but > its going to require a lot of processing power, and the timing aspects > will be very hard to get right. Fortunately I have a very slow machine to model, the faster instruction takes 12 microseconds. There are about 4000 PCBs, 1000 of which are JK flip-flops. The other 3000 have at most 4 And gates on each, plus wire-or so I would guess about 15,000 gates and 1000 flip- flops. I have scanned the 'Address Book' which lists all the interconnections in the machine. I want to OCR it and then write a program which generates C code to recursively process all changes in logic level for that clock cycle and then latch the data into the flip- flops at the end of the clock pulse. As there are so few logic levels which change on each clock cycle I would think that could be done in real time, after all a modern machine has a clock speed about 2000 times greater my 1301's 1MHz clock. > It has been done in the past, mainly to help designers test out their > designs, but they typically run several thousand times slower than the > actual machine. Presumably someone designing a new computer would be designing something faster than what already exists so the simulation would be often be running on a slower machine in the first place. > I remember there was something, possibly Java or such on that page, > but > it's long gone now. Unfortunately it wasn't something one could > download. That's one of the things that utterly sucks about the web. > You can archive it, but things that depend on a back end server > can't be > replicated without having what runs there (or a simulation thereof.) > It's sad that it wasn't released publicly. Now we have been appointed as the '1301 working group' of the CCS, the other half of the team gets a seat on the CCS committee (I'm too busy earning a living to keep going up to London every few months) so perhaps he can see if that is a possibility. > Most of Colossus was just circuitry, not much to program there, but > you > could code simulations of those circuits and provide code that does > similar enough things. (At least what little I know if it comes from > the book.) I think you need a knowledge of basic cryptography to make much sense of what the plug-able 'menus' do, knowledge I don't have. Roger Holmes.

15 years, 6 months

PDP-11 Controller needed to use a couple of RX33 drive

by bqt＠softjar.se

Pete Turnbull <pete at dunnington.plus.com> wrote: > On 17/06/2009 16:34, Johnny Billquist wrote: > >> > It's actually worse. The write enable signal apparently always gets to >> > both drives no matter what else you are doing. So when you write to one >> > drive, the other will also start writing, even if the head is moving >> > right at that time. I've had to recover an RD53 which was destroyed that >> > way. (Salvage as much data as I could, and then reformat the drive.) > > That won't happen unless both drives are also selected. Having the > write enable signal go to both drives at the same time is normal in > ST412 systems, and indeed all the signals go to all the drives at the > same time in such systems. Ok. I haven't checked all the details here, so it's part my research, and part information I've recevied from others. The only reason I even know about it is because I had to recover the data from a disk that they "destroyed" by doing this. >> > The funny thing is that DEC actually do write in the documentation that >> > it is not permissible to have two hard drives in a BA23, but that note >> > is not so easy to find, and if you don't have the documentation, it even >> > easier to assume that you can, since you do have connectors for two drives. > > The DEC information actually says that it's because of the power > requirements. The note that I read didn't say anything about power requirements, as far as I can remember. But maybe I should check the note I read again. This was about six years ago... (And as far as I know, the site is still running that machine, but they now have a couple of SCSI disks on it instead.) >> > I believe it's a hardware "bug", which can't be fixed without cutting >> > wires, and adding new ones. But maybe someone knows better here? > > Mine works, and I've not cut any wires. It could be that there are two revisions of the backplane? (Was it you who said that?) I know for a fact that a steel plant in Sweden stood still for five days because of this, six years ago. (Well, one part of it anyway.) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

15 years, 6 months

PCjr Telnet BBS Test

by aliensrcooluk＠yahoo.co.uk

Well, you did want us to test it out and try and break it, lol. Just glad I didn't bring it down completely. Is there a way to adjust the retransmit time depending on user location, or is that impossible / too complicated? Or will it be more friendly to everyone once it is increased a little? Regards, Andrew B aliensrcooluk at yahoo.co.uk --- On Sat, 20/6/09, Michael B. Brutman <mbbrutman-cctalk at brutman.com> wrote: From: Michael B. Brutman <mbbrutman-cctalk at brutman.com> Subject: Re: PCjr Telnet BBS Test To: "On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Date: Saturday, 20 June, 2009, 4:55 PM Andrew Burton wrote: > Yeah, I dropped by and had a blast (I'm Lonewolf10). > A neat all round experience. Just hope I don't get hooked on BBS's now! :) > > > Regards, > Andrew B > aliensrcooluk at yahoo.co.uk Your connection was interesting - I noticed it was driving my TCP/IP stack nuts.? (It was retransmitting a lot of packets while you were online - far more than normal.) Your message about being on a USB modem made me feel slightly better about it.? That, and being in the UK probably is just causing a very long latency.? My retransmit timeout on the TCP/IP packets is probably too low ... Mike

15 years, 6 months

One for Tony or other HP fetishists I suspect

by bqt＠softjar.se

Dave McGuire <mcguire at neurotica.com> wrote: > On Jun 14, 2009, at 10:09 AM, Gordon JC Pearce wrote: >> > I spotted what looked like an odd rubber-cased HP41 on a stall at a >> > car >> > boot sale. The guy also runs a small army surplus shop so although I >> > didn't get it there I might ask him about it if I go in during the >> > week. >> > >> > It had four openings at the back about the size of a matchbox end-on, >> > with brown flexiprint circuit stuff folded over plastic tabs in the >> > middle of each one. > > This description matches the expansion slots on a standard HP-41. > What's with the rubber case, I wonder? Some sort of protective cover > like the ones available for most mobile phones? I couldn't have described the ports any better myself. :-) The rubber case might just be one of the third party industrial cases for the HP-41 for it to better survive hostile environments. I don't think HP every did one, but I remember seeing other companies making them. No names pops up in my head right now, though. This was a long time ago. (Still have my 41CX around.) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

15 years, 6 months

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test-drb June 2009