test-drb

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101090 discussions

Is there a magic word to format a 8" Altos hard disk?

by aek＠bitsavers.org

Picked up an Altos 8600 that I bought on eBay yesterday, amazingly the Xenix actually came up, but the drive failed as I was tarring off the file system. I had another Quantum 2040, put it in, tried to run the formatter, but it says to call Altos, asks for a confirmation but just returns to the menu if you type 'y' 'Y' or 'Yes' so I'm assuming there is a magic word you have to enter. This is the same controller that the Z80 system uses (8000-14) so I'm guessing someone must have run into this before. I'm going to paw through the diagnostic binary to see if there is something that looks magical. Sound familiar?

9 years, 2 months

FP11-C Engineering Drawings?

by jnc＠mercury.lcs.mit.edu

> From: Al Kossow > i'll see about getting CHM's set scanned Oooh, great; thanks very much, _much_ appreciated! Noel

9 years, 2 months

FP11-C Engineering Drawings?

by jnc＠mercury.lcs.mit.edu

Is there a set of FP11-C Engineering Drawings online anywhere? Our favourite search engine didn't turn one up, and according to Manx: http://manx-docs.org/details.php/1,9306 there are none online. Noel

9 years, 2 months

Searching for a lost Macintosh TV (Texas)

by tothwolf＠concentric.net

I'm not really active in any of the classic computing communities apart >from classiccmp, so I would appreciate it if others could pass this message around and see if this computer ended up in the hands of a fellow collector. A good friend of mine who lived in Spring, TX (north of Houston) owned a black Macintosh TV (1993 vintage). During a move many years ago (late 2010), it mistakenly ended up turned in as ewaste. I only found out late this year (2016) that this had happened. Given how rare/uncommon these machines are, chances are very high that it ended up resold on eBay or similar instead of being scrapped. I have no records of the serial number of the machine, but according to my archives, I installed Mac OS 7.6.1 on it on May 5, 1998. It was also upgraded with an 8MB SIMM but still had the factory hard drive. If by some chance a fellow collector ended up with it, and if it still has its hard drive and files intact, my friend would really like to obtain a copy of her files (a disk image of the hard drive would be ideal). I happened to still have a backup of the machine on a zip disk from May 24, 1998, but she had continued to use the machine off and on for many years after that. I would also just like to know that the machine didn't end up scrapped.

9 years, 2 months

Searching for a lost Macintosh TV (Texas)

by ian.finder＠gmail.com

Props for for having a good sense of humor. It made me laugh. Seriously though I hate to say it but your quest feels pretty damn futile. I wish you luck either way, and would offer you my MacTV but it is long gone. If you can provide names of unique files or something that was on the drive- identifiable but not sensitive- it might help you. Like I said, there's nothing to key off of in your original post. I've hunted far rarer specific systems- smbx machines and the like that went missing from universities with good inventory control only one or two years ago- and had zero luck. Also do try Low End Mac and 68kmla, this is more relevant to those audiences. Cheers, - I On Monday, December 5, 2016, Tothwolf <tothwolf at concentric.net <javascript:_e(%7B%7D,'cvml','tothwolf at concentric.net');>> wrote: > On Mon, 5 Dec 2016, Ian Finder wrote: > > They sold 10,000 Apple TVs. That's a lot. >> >> You lost track of one ten years ago, and have given no real methodology >> for discerning it from any other- the number out there with OS 7.6 or 8mb >> of ram will be significant. >> >> Perhaps you should go door-to-door, or hang flyers. It would probably >> yield better results. >> > > [Sorry Jay, but I'm going to do this on-list.] > > Wow, Ian, you sure are helpful! Would you be willing to help me print up > and distribute those fliers? > > <insert giant ascii finger> > > :) > -- Ian Finder (206) 395-MIPS ian.finder at gmail.com <javascript:_e(%7B%7D,'cvml','ian.finder at gmail.com');> -- Ian Finder (206) 395-MIPS ian.finder at gmail.com

9 years, 2 months

Troubleshooting spooky & intermittent instability after power-up: Symbolics XL1200

by ian.finder＠gmail.com

Hi folks, I know this is a long shot but... I'm having a rather curious issue with one of my Symbolics XL 1200 CPUs, which I suspect may have a far more general cause. I have narrowed the issue down to the specific Merlin II CPU card I'm running- not the RAM, Jumper, I/O, backplane, power supply or any of that good stuff. My friend Doug has a rather pretty picture of the board in question on his site: https://symbolics.lisp.engineer/koken/albums/merlin-ii/content/img-4316/lig… It's basically a big wedge of PGA ASIC encapsulations and PALs, for those unfamiliar. The symptom is this. After a cold boot- a fresh power-up from no power applied- the system will hang after 30-40 seconds into the startup with a hard lock and sometimes memory bus issues. If I wait 10 more seconds or so, and hit reset, the system usually comes up fine for hours. If I hold the system in reset for a few minutes during the cold boot before proceeding, the system works fine. The repro rate is close to 100%. If the machine is off for a few minutes, then cold booted, the issue repros. It sounds as if something has gone thermally sensitive in a very deterministic manner. Can that happen with the tantalum caps on the board? Perhaps they are shorting intermittently for the first few dozen seconds? Again, the rest of the system is good- the issue follows this board and only this board no matter which chassis it runs in. All socketed ICs have been reseated. I know this isn't much to go off of, but anyone out there have experience with spooky "intermittent" yet 100% repro-able cold-power-up issues? I'll debug further of course, but thought I'd ask here. Thanks, - Ian -- Ian Finder (206) 395-MIPS ian.finder at gmail.com

9 years, 2 months

Black anti-static foam corrosion

by aek＠bitsavers.org

I was curious what the compound is that corrodes IC leads in old black anti-static foam adipic acid https://www.febo.com/pipermail/time-nuts/2008-July/032531.html and google for polyurethane and adipic acid https://www.jstor.org/stable/20619421 Corrosion on Metallic Tokens Stored in Polyurethane Foam

9 years, 2 months

Double Buffer RK11-C

by jnc＠mercury.lcs.mit.edu

> From: Fritz Mueller > Also, clues about an 11/20 interface for the FP11-B that were noticed > recently. I don't recall this; more details, if possible? Thanks! Noel

9 years, 2 months

HP 9872 Refurbishment

by cruff＠ruffspot.net

I hauled out my second 9872C today to clean it of rodent leavings and to scavenge the high voltage chart hold power supply board for my first 9872C. The table has some gouges in the surface, which appears to be a plastic film adhered to the table surface. Does anyone have experience repairing gouges, or found a suitable replacement film? Also, since I have it apart, I thought it might be good to image the firmware ROM set. They are marked Mostek MK36647N-5 and MK36648N-5, along with the HP part numbers. From the schematic, they appear to be 5V 8KB ROMs, so nothing fancy should be required to read the contents. It appears these might be MK36000N-5 mask programmed ROMs? P.S. It appears list submission doesn?t like digitally signed emails.

9 years, 2 months

Double Buffer RK11-C

by jnc＠mercury.lcs.mit.edu

> look at the lower right line of lights on the panel: ... and three bits > of Major State; now look at the RK11-C prints, connector B32: > ... Postamble, Checksum, Data, Header, Preamble. > ... > One thing I have been wondering about is that "RK11-C" - that implies > that there was a -B, etc. I wonder if this panel goes with one of them? Well, now that I look at a few more things I'm pretty certain the panel in that image goes with some currently-unknown RK11 predecessor to the RK11-C. Note those 5 'state' lines/lights, and then look at the 'Major States' RK11-C print (RK11-C-04, pg. 14 of the PDF version, RK11-C Enginering Drawings Feb1971). In the upper left corner there are a row of 6 flops, each labeled with one of those states (plus one for 'Idle'), arranged in a chain. So one light for the output of each flop... Now look at that display panel: 3 bits for 'Major State' - implying it is binary coded - likely implemented with a counter? Notice also the signal "COUNT MSR" ('Major State Register', I expect) - just what you'd expect to see if the major state had previously been held in a counter, not a string of flops. Why go to all the trouble to synthesize that signal (on the next page, RK11-C-05, "MSR Control") when you cou;d have used the individual composing signals to clock each flop? So my _guess_ is that in the previous version, they'd used a counter, but had had some problems (perhaps it was a binary counter, not Gray code, and the decoding into states was producing glitches), and had therefore switched to the string of flops. (This whole process makes me feel like a paleontologist, reconstructing some unknown dinosaur from a fragment of one bone, using a lot of complex reasoning >from small clues contained therein! :-) It would be most interesting to know if there are any signs anywhere of predecessors to the RK11-C. My suspicion is that they were produced in very small numbers - perhaps as prototypes, only internal to DEC. (If they'd had problems with glitches in the major state counter, they would not have wanted to release it as a product.) Or if it was released as a product, perhaps they were all recalled and replaced with RK11-C's because of the issues. As evidence for this, I point to the Spare Module Handbook, which lists only the RK11-C and -D - but _does_ list the KT11-B, a rara avis indeed. (More dinosaur bones... :-) This argues that the predecessor did not exist in the wild... Noel

9 years, 2 months

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