November 2015 - vcf-midatlantic

Museum Report
by Jeffrey Brace 23 Nov '15

23 Nov '15

4 visitors today. Steve Anderson was docent.

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Scheduled IRC or Online Hacking
by william degnan 22 Nov '15

22 Nov '15

All, There is a relatively active IRC at irc.slashnet.net / #vc. There is also an IRC for apple2 (forget the loc/name) that comes with the RasApple Debian Linux image. I was thinking vintagefed should put up an IRC called vintagefed or vcf. -- Bill

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Hoodies update
by Evan Koblentz 22 Nov '15

22 Nov '15

Our shirt guy asked me to visit his shop today because he wanted to ensure the correct shade of greenish-blueish. He mixed a few different inks while I was there. Took a few tries but we finally got a perfect shade. It's basically 2:1 of green and blue. He made a single screen print of our logo onto an old black t-shirt and it looked great. I am excited about how awesome it's going to look on the heavyweight new sweatshirts.

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Zilog System 8000
by Herb Johnson 21 Nov '15

21 Nov '15

Microtech Dart wrote: > Actually, I've already done something that works well for a lot > of what you mention. [With] my Universal QIC tape reader.... > I've read a number of different head/track configurations > with this, by finding the tracks of the 9 that overlap with > the 4, and choosing the correct direction on my > manual switch control. > > http://microtechm1.blogspot.com/2015/09/ >kennedy-6450-tape-drive-data-format.html I have a question, but first some set-up for it. I have a point in spelling this out. Over the years, a number of people have read off binary data streams from either cartridge tape drives or very old hard drives; they store the binary samples as huge files (relative to the original data). And there are devices like the Catweasel series of cards, which operate floppy disk drives and sample their binary data streams. "Sampling" means there's many bits saved, to detect each "bit" of real data on the medium. Sometimes, these methods aren't sampling, they include the drive's "decoder" to produce actual binary data from the media. So a recovered "bit" is a real "data bit". But not all of those who produce these methods, take the next step of decoding the samples into blocks of original-as-recorded data; and then decode the blocks back into the original files which were written-to the storage devices in the first place. result: there's data "recovery" but not file recovery. I've explained what I mean by that. Now, I've looked at the microtechm1 blog. Since like most blogs it's written as a sequence of events, there's no obvious-to-me summary of current progress, beyond the "most recent" entry. I don't have time to read all prior entries. I can see there's progress on decoding the recovered data; and some hints that data at the "block" level may have been recovered. Some posts about "here's a binary extraction". This is good work, this is hard work. But I'm not clear about how far it has gone; and I made a good-faith effort to look. So here's my questions. Have you 1) reproduced the actual block-by-block data from the tapes you've processed ? 2) do you have programs to decode the blocks to interpret checksums, block numbers and so on? and 3) can you therefore process the successful blocks further to recover actual, individual files? I'm not trying to minimize all the good, and necessary, technical work done. I'm asking if files have been extracted, and if so where they may be, and where the supporting programs may be. Why am I interested? I "get" your point, these methods may be useful to me, in recovering other data from other tapes or devices; as was suggested. Herb Johnson -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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An object lesson in modern vintage computing
by Herb Johnson 20 Nov '15

20 Nov '15

...so Wed noon, someone who writes for an online personal-tech lets-make-it-whee Web site, emails me. "I was asked to write about a possible trend toward retro tech. Would you answer questions like this? 1) what's so fascinating about retro tech? Is interest increasing? 2) is retro tech practical or nostalgic? 3) does retro tech have any advantage over modern tech? You can have me email or phone you, let me know." [I'll remind readers, my Web domain is "retrotechnology.com".] Of course, I have a life, so I did not respond that same second. It was the next day, just about 24 hours later, I emailed "OK, contact me with your questions, and give me some clue about your audience. Because, most of my answers will depend on what kinds of people you are talking about." I made the obvious-to-me statement that there's different generations of people, who are involved with vintage computing. They have different points of view; the questions I was given suggest as much. Response back, in six minutes: "the editors moved up my deadline and the story already has been filed. Thanks for the offer." Thus I was given, an object lesson about modern vintage computing. Namely - there's no time. It must be now, just like modern computing and modern "life". My view, is that the preservation of vintage computing hardware and methods, is to preserve the object lessons (of development, production, business) learned then, on their own merits; and on the merits of developing technology in a resource-poor environment, which could occur again. Put another way: then, we had time but no resources. Today, we have too many resources, but no time. If this is too cryptic, you may have to think about it awhile. Herb Johnson retrotechnology.com -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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Zilog System 8000
by Oliver Lehmann 20 Nov '15

20 Nov '15

Hi computer history enthusiasts, I hope that it is ok that I signed on to your list. I am from germany and I'm looking for information about the Zilog System 8000. I know that you owned at least one in the past. I don't know if you still have it, but I hope so :) Bit more about what the background of my question is: - I own a Zilog System 8000/21 but neither do I have a harddrive for it nor do I have a working tapedrive or any tape medias. - A friend of mine also got a Zilog System 8000/21 lately but his harddrive is broken (heads do not find track 0), and his tape drive capstan went to "gum". He got a noriginal Zilog ZEUS (Zilogs UNIX) tape media but with the broken drives no way of backing it up or retrieve at least its contents. - Today I found out, that another enthusiast from a local university also has a System 8000/32 (newer than /21 with SMD harddisks) in the uni museum. He has a dying harddrive, a working tape drive but no media. You see... lots of "missing", "dying" and so on.... I wonder in what condition your System 8000 is. In the past (2009 and 2012 iirc) I had contact with Jeff Jonas. He was trying to back up the tapes you guys have for the system. But iirc his problem was also, that the capstan of your System 8000s tape drive went literally to fluid.... I wonder if there is any status update? We really could need those tape images and it looks like there are not much System 8000s around any one - and even less installation medias. Beware - even if the tape might fit into a regular QIC-11 Tape drive - its encoding is MFM - so far from any QIC standard. It will only work with the original Tape drive from the System 8000. Please be extremly cautionous with the tape medias. They might be the only ones left still be readable... who knows.... Before you try anything - try it with unimportant tapes many times before you risk the Zilog tape. Backing up over serial can not be recommended as the tape will fetch data more then 10th as fast as the SIO can pump it to a remote machine. This will lead to a permanent stop/start mode the tape will work in resulting in maximum stress for the Zilog tape. I would _not_ recommend this. You see - I'm quite careful when it comes to your tape, but still seeking out for any posibility to aquire a dump of it somehow. Any information about "my" S8000? Feel free to look it up at http://www.pofo.de/S8000/ Regards, Oliver!

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Re: [vcf-midatlantic] An object lesson in modern vintage computing
by Mike Willegal 20 Nov '15

20 Nov '15

I’m guessing that Evan knows what’s going on behind the scenes, but I’ve found media types need a response within about 45 minutes (on average) or they will have moved onto the next thing. regards, Mike Willegal

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DEC Real Time Clock board wanted - ETOS
by Jack Rubin 19 Nov '15

19 Nov '15

I'm hoping to build a system to run ETOS, a PDP-8 multiuser system. One of the requirements is a system clock for time slicing and stamping. I'm looking for either an M882 (line frequency) or M8830 (crystal controlled) clock card. Anyone have a spare? Working preferred but anything will do. Happy to buy or trade. Thanks, Jack

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Unix manuals available
by Kelly Leavitt 18 Nov '15

18 Nov '15

Miscellaneous manuals for Unix software. Wordperfect for Unix dBase for Unix Lotus 123 for Unix SCO Unix manuals Any interest? I can bring them to Festivus if I get them out of the attic in time. Kelly

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Zilog System 8000
by Herb Johnson 17 Nov '15

17 Nov '15

> Your tape drive has also a capstan which went to goo over the past > 30 years, so please do not just put them into the drive without > fixing that first. The following are suggestions I'm not implemented, but they seem plausible to me based on other's discussions and some related experience. Please report any results. Consider making another capstan, otherwise called a "pressure roller". In the end, it's a stiff rubber wheel on a bronze bearing with an internal diameter to fit on some roller. Examine your drive or others of same brand and model to determine dimensions. Keep in mind: it's the metal drive roller which determines tape speed, not the roller. It's possible a piece of bronze can be machined to be the correct size, then rubber molded around it, and then carefully machine the rubber to the correct diameter. There are two-part rubber compounds which when mixed and cured are quite stiff. Or, obtain another larger roller and cut it to fit. Rubber can be abraded in a lathe at low speed. Stiff rubber pieces are often sold as furniture bumpers or "corks" for pipe and "test tubes". These machining operations may require practice, and old tape drives can be found to make test rollers - as all you really need to do is drive the capstan motor and monitor tape speed for stability. Any signal on any tape can be watched on an oscilloscope and tape speed determined. A stable signal means tape speed is stable, a wriggly signal means tape speed is varying, probably at the rotation rate of the capstan pressure wheel, or rotation rate of the drive capstan, or due to other irregularities. Herb Johnson -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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