test-drb

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101090 discussions

release dates of early microcomputer operating systems, incl. Intel ISIS

by jnc＠mercury.lcs.mit.edu

> From: Dave G4UGM > although ENIAC first ran a program it was stored as acoustic waves I don't think ENIAC used acoustic delay storage? Perhaps what you're thinking of is that in the original ENIAC usage, there was no 'program' as we now think of that term; the machine had to be configured (via connecting up computing units with cables) for each separate problem, i.e. more 'configurable' than 'programmable' (at least in the Turing machine sense). Hence the debate over whether it or the Baby was the first 'computer'. Noel

10 years, 7 months

A poltergeist in my machine?

by jnc＠mercury.lcs.mit.edu

> From: Jerry Weiss > Check if the -5v charge pump is stable and supplying the correct voltage. > I recall a problem ... in which the on board pump went slowly bad. > Depending on the data content and tolerance margins for the memory > chips, we saw very erratic problems. That doesn't sound like my problem; this board was _consistently_ failing hard (would not write _any_ data, no-how, no-where), and then *poof* it was pretty consistently totally working (passing memory diags, etc). And the change from 'consistently not working at all' to 'working completely' happened when I 'touched' (see below) that pin with a probe. So either i) it was pure coincidence (possible, I suppose), or ii) there was some wierd causality. > From: Jon Elson > 1. There was a conductive hair on the board, and you knocked it off > with the probe. I'd brushed the board pretty comprehensively with a toothbrush to get all the dust off. (Yeah, I know, static - but it's pretty humid here right at the moment! ;-) > 2. There was a bad solder joint and the pressure of the probe broke > through the oxide. ... This is my highest probability guess. ... > 3. The chip has a bad internal wire bond, and the pressure on the lead > made it work. Well, I was using a DIP clip, so the pressure on the pin was pretty consistent before and after. Yeah, attaching the 'scope probe to the second pin would have wiggled the clip a tiny bit, but I'm still dubious. My current best guess, after sleeping on it, relates to the fact that the 'magic' pin was an output from a delay line. Delay lines, in that era, were apparently potted confections of inductors and capacitors. So maybe the extra current drain with the probe on somehow affected one (or more) of the capacitors in the delay line? A total WAG, but it's very mysterious! Noel

10 years, 7 months

release dates of early microcomputer operating systems,

by Wayne.Smith＠warnerbros.com

> Date: Tue, 15 Sep 2015 03:03:05 -0600 > From: Eric Smith <spacewar at gmail.com> > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Subject: Re: release dates of early microcomputer operating systems, > incl. Intel ISIS > > Are you sure ISIS (one) didn't have disk support? I thought that was > shipped with the first Intel MDS-DOS floppy systems for use on the > MDS-800 in 1975. A 1975 edition of the MDS-DOS Operator's Manual is > listed among other Intel manuals at: > > http://www.intel-vintage.info/aboutme.htm Looked up the copyright registration for the manual and related items: A712678. MDS-DOS diskette operating system operator's manual 79 p. Add. ti: Intel diskette operating system microcomputer development System MDS-DOS operator's manual. (c) Intel Corporation; 22Dec75. A712670. Intel diskette operating system microcomputer development System MDS-DOS hardware reference manual. 1 v. (c) Intel Corporation; 15Dec75.

10 years, 7 months

DEC Alpha 3000 Model 600

by rodsmallwood52＠btinternet.com

I thought it might be nice to have a DEC based graphics work station. I had the Alpha, a high res monitor and the Hobbyist Media CD for ALPHAVMS 8,3. (yes the system supports 8.3) SFSG .. So CD in the drive and switch on. First a nice colour graphics demo/test. Then the nomal system level stuff. >>> prompt, enter SHO DEV and our CD drive shows as DKA400 just where it should be. So Boot DKA400: and off we go. After a while a menu appears from which you can load layered products you need. It gets part way through the load and falls over with a data error. The cd is a real bought and paid for Media CD and is not a copy. Before I do a lot of tedious emaling (HP have taken the Hobbyist program in house) has anybody successfully loaded an Alpha with ALPHA VMS 8.3? Regards Rod

10 years, 7 months

ZX Spectrum disk interfaces

by lproven＠gmail.com

A question born only of idle curiosity. In thge 1980s, I bought an MGT +D disk interface for the Sinclair ZX Spectrum: https://en.wikipedia.org/wiki/%2BD In the end, I traded mine in for its upmarket cousin, the DISCiPLE: https://en.wikipedia.org/wiki/DISCiPLE (I link to WP as I originally wrote those articles, IIRC. :-) ) I have noticed that multiple people have now cloned the +D: http://sintech-shop.co.uk/sinclair/-d-disk-interface-clone/a-6196/ http://www.rwapsoftware.co.uk/spectrum/spectrum_storage.html#plusd But this post, from FB, claims that the Beta Disk interface can handle high-density drives, giving 1.5MB per disk: https://www.facebook.com/groups/speccy4ever/permalink/1237322356346334/ Given that HD floppies and drives are far more readily-available than DD these days, how come most 8-bit interfaces can only handle DD? Is it purely a data rate issue? -- Liam Proven ? Profile: http://lproven.livejournal.com/profile Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven Cell/Mobiles: +44 7939-087884 (UK) ? +420 702 829 053 (?R)

10 years, 8 months

PDP-11 manuals scanned/scanning

by jnc＠mercury.lcs.mit.edu

OK, so I finally got set up to scan manuals, with a scanner with a document feeder, so I don't have to sit there and feed the beast! So now I can scan in a number of 'missing' (online, at least) PDP-11 manuals which I happen to have. The first thing through the machine was the DZV11 Technical Manual (which Paul Anderson was gracious enough to loan out, to enable it to be put online - thanks Paul!), now available here: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/EK-DZV11-TM-001_Jun78.pdf (as always, please download/distribute/replicate to other repositories). I also did the 11/34 cache board user manual, now here: http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/EK-KK11A-UG-001_Oct78.pdf I have also gone through my set of manuals and prepared a list of all the ones which aren't online. I will slowly be scanning these in, but if anyone has a particular need for any of these, please let me know, and I'll move it to the top of the queue. They are: EK-881PC-UG-003 881 Power Controller User Guide EK-H9646-UG-002 H9646-AH/AJ Cabinet System User Guide DEC-11-H40SA-B-D PDP-11/40, -11/35 (21 Inch Chassis) System Manual EK-FP11C-OP-001 FP11-C Floating Point Processor User's Manual EK-1184A-TM-PR4 11/84 Technical Reference (Preliminary) EK-1184E-TM-001 PDP-11/84 System Technical and Reference Manual EK-1184E-MG PDP-11/84-E User's and Maintenance Guide EK-DHU11-TM-001 DHU11 Technical Manual (although IIRC that last is in a glued binding, so it's not really amenable to being auto-fed unless I rip it apart, which I am loathe to do). I also have: DEC-11-HR6B-D PDP-11 Conventions Manual but that's in print format (i.e. large pages), and I'd have to hand-feed that one through my A3 scanner. The auto-feed scanner I have is an older Epson, which I got on eBay for not very much. I'm using just the Twain driver from Epson; I'm doing my scanning >from IrfanView (a _very_ useful image tool, which if you don't have it, download it, it's free) which spits out the CCITT4 TIFF's directly - and can even number the output files backwards - incredibly useful when scanning hunks of double-sided pages on a single-sided scanner! If anyone wants to get set up to scan manuals, and wants to copy what I did, let me know, and I'll provide details. Noel

10 years, 8 months

FS: PDP-11/55

by rob＠krten.com

Hi all, I have a PDP-11/55 for sale (Ottawa, Ontario, Canada). Bids open until 2015 09 15, buyer to arrange shipping, I will have it wrapped and ready to go. Please visit: www.krten.com/~rk/museum/index.html For pictures, detailed inventory and contact info. Sealed bids via eamil please. Winner will be notified 2015 09 16, machine will be ready to ship same day. Must be shipped / picked up no later than 2015 10 09. Sold AS-IS / where is, untested, unpowered since received. Comes with H960 rack and 2 side panels. Cheers, -RK -- Robert Krten Visit me at http://www.ironkrten.com

10 years, 8 months

M8192 KDJ11-A ZKDJB2 XXDP Test Failure

by holm＠freibergnet.de

While checking my repaired KDJ11-A M8192 Board with xxdp I get the following error: BOOTING UP XXDP-XM EXTENDED MONITOR XXDP-XM EXTENDED MONITOR - XXDP V2.5 REVISION: F0 BOOTED FROM DL3 124KW OF MEMORY NON-UNIBUS SYSTEM RESTART ADDRESS: 152000 TYPE "H" FOR HELP ! .R ZKDJB2.BIC ZKDJB2.BIC ERROR WHILE TESTING BOARD FUNCTIONS ERROR # =001166 ERROR PC =040662 043632 @ The Board is working flawlessly otherwise. Can please someone with such a CPU can do a similar test and what does this error mean? I get this error with two different J11 Chips. In the Docs ( http://bitsavers.trailing-edge.com/pdf/dec/pdp11/xxdp/PDP11_DiagnosticHandb…) is shown thatthe test should ask for a Switch Register setting, in my case it doesn't. Is the test defective? Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583 www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741

10 years, 8 months

R: Re: 12" Floppy Disks

by supervinx＠libero.it

May be he's a fisherman :) They tend to oversize everything :D -------- Messaggio originale -------- Da: Fred Cisin <cisin at xenosoft.com> Data:15/09/2015 14:01 (GMT+01:00) A: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Oggetto: Re: 12" Floppy Disks On Tue, 15 Sep 2015, Adrian Graham wrote: > Morning folks, > I've been contacted by a teacher who's looking for any information about > 12" floppies. Am I imagining that they really existed? I'm sure I've seen > one or seen adverts for them, maybe at Bletchley Park. Others he's > contacted think he's getting confused with 12" laser discs but I'm not so > sure. > Anyone? First, how old is he? If he is under 50, then he may be looking for the EARLY_PERCEPTION 12" floppy.? "Man, those things were HUGE! ENORMOUS! When my elementary school teacher brought one into class, it was bigger than my foot!" What he is misremembering is an 8" disk. If he is over 50, then he may be looking for the FADED_MEMORIES 12" floppy.? "Man, those things were HUGE! ENORMOUS!" What he is misremembering is an 8" disk. Or, he may be looking for the CREATIVE_MARKETING 12" floppy. When TVs were round, the measurement was the diameter.? When they stopped being round, the measurement was the diagonal, or largest length.? More recently, they've started to round up.? And, now, I think that they are measuring the diagonal of the box that it is shipped in.? The diagonal of an 8" disk jacket is about 11", rounded up to 12" Very large objects tend to be remembered as even larger.? I have a [damaged] 24" platter from a hard disk.? When mentioned later, most people remember it as being "three or four feet diameter!" We have had numerous prior queries about the 12" floppies.? One tipoff is that sometimes the person asking will remember that floppies had TWO sizes, "five inch" and "twelve inch".? 3.5" will either be called "three inch", or "hard disks"!? It is simply a misremembering of eight inch. As Eric pointed out, floppies STARTED at 8", and went DOWN from there. But, could we be wrong? Of course. But, I'm willing to bet $20 that nobody can send me a 12" floppy. -- Grumpy Ol' Fred???? cisin at xenosoft.com

10 years, 8 months

Even more PDP-8/A weirdness (was: Re: PDP-8 diagnostics SR settings?)

by charlesmorris800＠centurytel.net

More testing this evening. Drive 1 ran for 8 ten-minute AJRLIA read-write passes before I stopped it, with a single error flagged during pass 6: WD1 0235 WD2 0000 ER 4001 CB 1117 indicating a Data CRC error and a Read header without CRC command. Not completely unexpected, a lot of data is being read and written and there is a soft error rate of 1 in 10^9 bits and hard error rate of 1 in 10^12, IIRC. Meanwhile I keyed in the Oscillating Seek program from the RL01/02 Users Guide manual (page C-6) and set it for 511 cylinders. It seeks without any problems swinging the head from Track 0 to Track 511 and back, on both drives. No Fault, no nothing except seeking. Perhaps I was overthinking the "wrong command" theory. I did reseat the 2708 EPROM (state machine) on the controller card. One VERY interesting thing I learned from a close reading of the manual and this test program though: The controller reports Ready status *immediately* when a seek command is given, even though the seek has not completed!! (pg. 5-15, para 5.3.4) And that seek can take up to 100 ms for 511 tracks on an RL02. A long time in computer terms, even at 1.6 us per instruction cycle... Now I'm wondering if AJRLHA diagnostic doesn't wait long enough for the seek to complete before trying something else. The Oscillating Seek does (by calling for a dummy Read Header command). Still don't understand the Write error that shouldn't have been there from that diagnostic... Not happening tonight though. I can run RL2FMT on either drive, boot OS/8 with no problems (other than the brief flash of both Fault lights), PIP files from one drive to the other. Could OS/8 do its initial Seek without waiting long enough for it to complete, too? Would love to hear from any experts on the internal workings of OS/8 especially relating to RL02's. -Charles

10 years, 8 months

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