- vcf-midatlantic - lists.vcfed.org

Festivus Entertainment Thread
by Jeffrey Brace 28 Nov '15

28 Nov '15

Who is bringing what for entertainment? Equipment, games, DVDs?

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Modern Core Memory Implementation
by J. Alexander Jacocks 28 Nov '15

28 Nov '15

All, I just finished reading these posts, and watching the accompanying YouTube videos, and I was absolutely blown away: http://eab.abime.net/showthread.php?t=79346 Amazing work, and really neat to see someone doing such a modern reconstruction of core. Definitely worth a look. - Alex

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Core memory
by william degnan 28 Nov '15

28 Nov '15

Getting intermittent stuck bits with my pdp 11 non parity core stack. Without getting into a lot of detail, I noticed that something is causing the inhibit to fart high every so often, effecting address bits and to a lesser extent data bits. I have been doing a lot of research. My question.. aside from manuals and the tech docs does anyone have any anecdotal info, advice or test procedures related to DEC core RAM and intermittent stuck bits? Shielding tips? Bill Degnan twitter: billdeg vintagecomputer.net

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Heathkit 3400's
by william degnan 26 Nov '15

26 Nov '15

I remember ~10 or so people got nice cheap mostly working Heathkit 3400's at VCF 10 last year. Anyone do anything with theirs? Someone today sent me a question through my web site about terminal settings for the 3400 monitor program, I pulled my 3400 system out and fired it up to test and confirm mine is 2400 7/n/2 -- Bill

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Manuals For Sale or trade or for the V.C.F.
by Kelly Leavitt 26 Nov '15

26 Nov '15

Just found several more boxes of manuals. Specifically, I found about 300 pounds of old TRS-80 model II, 12, 16, and 6000 manuals (both hardware and software). I have most of them. Looking for a loving home. Lots of Xenix, programming, database, and OS manuals as well as hardware reference manuals. I want these to find a home, not the recycle bin. The "federation" has first dibs if they want them for a donation. Any interest? Make an offer direct to my email. Two manuals I found that I've been looking for for several years are the Informix for Xenix and the VideoTex and Office System server manual. Not software yet, but I'm just getting started.

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Re: [vcf-midatlantic] UPDATE -- Festivus food thread: Who'sbringing what?
by VAXman＠tmesis.org 25 Nov '15

25 Nov '15

Bill Dromgoole via vcf-midatlantic writes: >I will bring a case of Yeungling beer. I will also bring a portable >projection screen. The screen is available for donation to VCFederation >if needed or wanted. Also there are three cases of fanfold pin feed >paper up for grabs if VCF doesn't want it. Pottsvile piss! While I was weened on that stuff, I wouldn't drink it today!

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v/68
by william degnan 25 Nov '15

25 Nov '15

anyone running a v/68 system (motorola UNIX-ette) -- Bill

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Re: [vcf-midatlantic] IBM 360 Panel in NYC
by Corey Cohen 23 Nov '15

23 Nov '15

We give you a letter describing your donation. You and your tax advisor have to figure out what it's worth and what it does to your taxes. corey cohen uǝɥoɔ ʎǝɹoɔ > On Nov 23, 2015, at 4:29 PM, Bill Sudbrink via vcf-midatlantic <vcf-midatlantic(a)lists.vintagecomputerfederation.org> wrote: > > Evan Koblentz wrote: >> It's certainly interesting, but we do not purchase artifacts. > > Yes, but you give generous tax breaks. That's the whole idea, > right? > > Bill S. > >

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IBM 360 Panel in NYC
by Jason T 23 Nov '15

23 Nov '15

This may be of interest to the museum: https://www.reddit.com/r/vintagecomputing/comments/3tzepr/front_panel_of_ib…

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PDP 11 on eBay just closed
by Chris Fala 23 Nov '15

23 Nov '15

Anyone here get this? It was fun watching it. Within a few minutes it went from around $600 to almost $10,000. http://www.ebay.com/itm/191737673720

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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 20 Nov '15

20 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 18 Nov '15

18 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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Replicating Boot Drive, VAX
by william degnan 18 Nov '15

18 Nov '15

Reading up about VAX 4000 support. I have a three drive 4000-200 in the BA430 enclosure. It also has a tape drive and ethernet device Question - Do you formerly MARCH and now VCFedgerationites who are also VAX users with similar systems maintain more than one bootable drive as a rule of thumb? I am not detecting any issues with my primary drive but I don't want to take chances. Just curious what kinds of support strategy ideas you may have. I have the manuals and have been reading up on backups, etc. I just got a new hard drive and I need to replace a bad drive, amd I was thinking now would be a good time to set as the 2nd bootable drive, before I put anything on it. I thus could experiment with one drive knowing I have a fall-back that will boot. I am also reading up about how the three drives worth together, it's not as simple as "three independent hard drives" as far as I can tell. Interesting and complex file system. -- Bill

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Wanted: Commodore PET
by Todd George 18 Nov '15

18 Nov '15

First, my apologies if this somehow shows up on the list twice, I think there was an issue with how I have my email that is registered with the new list configured. Anyway... Been looking for a Commodore PET for a while. None have shown up locally on CraigsList. The eBay ones are either too far away (trying to avoid huge shipping costs and/or damage) or are overpriced. Anyone with MARCH/VCFed have an extra or spare (need NOT be working) that they'd like to (or be willing to) part with (for someone who would appreciate it immensely)?? I would like one with a standard keyboard, not the chicklet. Otherwise, I've got very little preference. As I said, shipping tends to be really expensive on these. Something local-ish would work better. Willing to trade stuff or pay cash. Festivus? Contact me off-list. Thanks!!! -Todd

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Semi-OT: FS: 20 MHz Leader dual channel oscilloscope
by Systems Glitch 17 Nov '15

17 Nov '15

All, I figured I'd offer this to the group before listing it on eBay. I've got a small "student" oscilloscope, I believe a LS 1020, for sale. Limited in bandwidth but adequate for most vintage computer repairs, general hobby use, et c. It's a barebones unit from the Virginia Tech physics department, completely analog with no storage, but it does work and has a nice, bright CRT. It's fairly small and light. I can confirm model numbers if anyone is interested -- it's still in the truck with the rest of the test equipment from the VT Surplus Auction. Looking for $75, doesn't include probes but I'm sure I can dig up a pair for a little bit more. I can ship, but would prefer to exchange at the festivus get-together. Thanks, Jonathan

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ODYSSEY 2 on Craigs list in LI
by Kelly Leavitt 17 Nov '15

17 Nov '15

http://newyork.craigslist.org/lgi/sys/5313961495.html I want it, but I don't want to drive out there. Anyone else interested? Kelly

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Zilog System 8000
by Herb Johnson 17 Nov '15

17 Nov '15

http://pics.pofo.de/gallery3/index.php/S8000/Repair/tapedrive If this is the correct series of photos for your tape drive, then the rubber roller which is driven by the tape drive motor IS, repeat IS, of critical dimensions. Please verify. Herb Johnson -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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Re: [vcf-midatlantic] Lack Of Windows 3.1 Technicians Causes Traffic Backup At French Airport
by VAXman＠tmesis.org 17 Nov '15

17 Nov '15

Kelly Leavitt via vcf-midatlantic writes: >A little OT for this group: > >http://consumerist.com/2015/11/13/lack-of-windows-3-1-technicians-causes-tr= >affic-backup-at-french-airport/ One of the reasons I do NOT fly into Paris. I fly into London and take the Chunnel train to the other .EU countries! WEENDOZE... the only winning move is not to play!

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Lack Of Windows 3.1 Technicians Causes Traffic Backup At French Airport
by Kelly Leavitt 17 Nov '15

17 Nov '15

A little OT for this group: http://consumerist.com/2015/11/13/lack-of-windows-3-1-technicians-causes-tr…

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Floppy Days Podcast #49 on the TI-99/4A
by Randall Kindig 17 Nov '15

17 Nov '15

Floppy Days Episode 49 http://floppydays.libsyn.com/floppy-days-49-ti99-interview-with-jim-fetzner… <http://floppydays.libsyn.com/floppy-days-49-ti99-interview-with-jim-fetzner…> The TI-99/4A - History, Interview with Jim Fetzner and Mark Wills In the home computer timeline, I’m currently covering computers released in the era from 1979 to 1980. Next up is the TI-99/4A. When I went to research the TI-99 I found an incredible amount of information about the machine and an involved, vibrant community surrounding it. As a result, I pulled in as many experts as I could find to be involved in providing information about this very interesting machine. I got so much involvement, and found so much information, that I will be covering the TI-99 for the next several shows. That will include the typical topics, such as history, tech specs, modern upgrades, emulation, Web sites and much more, as well as interviews with some TI luminaries. As I typically like to cover the history of the machine first, that will be the topic of the first couple of shows. For the history segment, I was lucky enough to find a couple of people who have an incredible history with the TI-99, Jim Fetzner and Mark Wills. Jim has an extensive, multilingual library of all things TI and possesses some very interesting hardware items related to the TI-99, as you will hear. Mark is the author of TurboForth for the TI-99/4A and has been involved in the TI-99/4A scene pretty much since 1983. He’s also English, living in the UK, so he has a rather British take on the home computer wars. Since the interview piece I typically do with the co-hosts before covering the main topic took so long and turned out to be so interesting in it’s own right, I decided to break out the interview into its own show and the next show will then cover just the TI-99 history with the help of these two gentlemen. Randy Kindig host Floppy Days Podcast floppydays.com <http://floppydays.com/>

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Re: [vcf-midatlantic] Festivus food thread: Who's bringing what?
by VAXman＠tmesis.org 17 Nov '15

17 Nov '15

Evan Koblentz via vcf-midatlantic writes: >Please reply with what you're bringing. Ask if you are unsure about >anything. I will, as they've already been requested in another Festivus thread, bring my homemade pork ribs as I have for the past few Festivus. If Corey's Penn Brewery will be supplying us with zymurlogical libations, I'll likely leave the Guinness kit home.

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Re: [vcf-midatlantic] Roland MT-32 equivalent?
by Mike Loewen 17 Nov '15

17 Nov '15

On Mon, 16 Nov 2015, John Heritage john.heritage(a)gmail.com [midatlanticretro] wrote: > I have a few Atari ST's (including a Mega STE) and I'd like to get > something like a Roland MT-32 for it to decode MIDI from games/demos that > support it to my stereo receiver.. They're a little hard to find these > days, or at least seem to be for a reasonable price. Does anyone have any > alternative classic MIDI synthesizers they'd recommend? > > I also have a MIDI port box for Amiga I have not tried yet so hoping I can > use this synth for that too. > > Thanks so much! > John H If you want an FM synth module rather than a LA module, you might look for a Yamaha FB-01. Similar vintage to the MT-32, and a lot cheaper. Mike Loewen mloewen(a)cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/

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Worst-kept secret: VCF East, April 15-17, 2016
by Evan Koblentz 16 Nov '15

16 Nov '15

I think a lot of people know this already, but VCF East XI (yeah, I'm using Roman numerals for now) is April 15-17, 2016. Friday -- classes + some kind of primitive software hackathon Saturday/Sunday -- morning keynotes + the usual daytime stuff As previously announced, Saturday's keynoter is Stewart Chiefet. :) Still working on a keynoter for Sunday. We had Dave Walden of BBN and ARPAnet renown, but he backed out due to health concerns.

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Simpson 262 Series E
by Paul Birkel 16 Nov '15

16 Nov '15

As long as we're talking about Simpson 260 multimeters ... I have a Simpson 262 Series E that suffered battery-failure (x2) in its former life. I'd like to put it back into service (for the reasons that Dave states, below), and aside from fixing the corrosion at the battery contacts (pointers anyone?) I've been "put off" by the problem of finding affordable modern substitutes for the pair of 15v batteries used in the higher resistance ranges. Any suggestions for a suitable substitute for the 30v (total) battery requirement? -----Original Message----- From: vcf-midatlantic [mailto:vcf-midatlantic-bounces@lists.vintagecomputerfederation.org] On Behalf Of David Riley via vcf-midatlantic Sent: Monday, November 16, 2015 10:46 AM To: vcf-midatlantic Cc: David Riley Subject: Re: [vcf-midatlantic] Apple IIe Voltmeter On Nov 13, 2015, at 11:59 AM, Herb Johnson via vcf-midatlantic <vcf-midatlantic(a)lists.vintagecomputerfederation.org> wrote: > > I prefer analog meters when making "runs" of comparative measurements. It's easy to see if one reading is "more" or "less" than another, the needle is literally in different positions. I prefer them for that and, for diagnosing intermediate or "wandering" problems (or quickly checking continuity), it's MUCH easier to see a needle moving than wait for the update of an LCD. > I've found variations in current measurements among several Simpson 260 meters (and among their scales) I've acquired. My guess is that some of the shunts were "cooked" by excessive current, or corroded by time and tide. I have not yet gone to the trouble of diagnosing them, I simply use the meters that have the best readings through the procedures noted. They are cheap today. I've definitely cooked current shunts in both digital and analog meters. Nothing is immune, even the fused ones (those fuses do have a finite blow time, which is more than enough to damage something if you accidentally touch mains). > Why? Given the "digital is better" bias these days, only a few people call out the Simpson 260 as a valued instrument - Dave McGuire for instance, in that email list we used to use. Digital is marginally better in situations where you need to record a number, but that's really just laziness. They can actually be more precise where that matters, but it seldom does. And I like the autoranging of digital meters, but that goes back to laziness. I have a very nice Fluke 87-V that I use for just about everything, but there are a lot of times I wish I had a dependable and portable analog meter as a counterpart. - Dave

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Current Loop Converter Update -- Modularizing
by Systems Glitch 16 Nov '15

16 Nov '15

Continuing the saga of designing a "tries to meet all requirements" current loop converter, I've decided to redo it as a modular design with separate modules for: - Loop supply - Receive converter - Transmit converter This will make the board smaller, plus you won't have to populate the modules you don't need. They'll also be available for inclusion in other projects. The edge connector spacing is intended to mate with Digi-Klips or have 0.1" pin headers soldered on. It's a single-inline connector, so it's breadboard friendly too. Here's some pictures of the 24V isolated loop supply module: http://imgur.com/a/U9RMK I'll probably end up using that module in projects not related to the current loop project, too! Thanks, Jonathan

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Re: [vcf-midatlantic] Festivus food thread: Who's bringing what?
by VAXman＠tmesis.org 16 Nov '15

16 Nov '15

Evan Koblentz via vcf-midatlantic writes: >>> I'll be bringing some homebrew; I have a winter warmer that's come >out = >> pretty well that I can bring at least 12 of (maybe a case). >Probably = >> not enough to stave off Brian bringing the good black >stuff. :-) Evan, > > I wasn't planning to lug the Guinness to Festivus. > I won't be staying the > evening which would not be a problem because >I've left the kit there in the > past and I retrieved it the next day. >However, there's a rocket launch on > that Sunday, so I won't be able to >pick up the kit on Sunday. > >No problem, there will be plenty to drink between Corey L.'s beer + >David's + whatever anyone else brings + Neil's apple cider. I may bring some beer, just not the whole keg/kegerator.

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[midatlanticretro] New York Historical Society : Silicon City: Computer History Made in New York
by Herb Johnson 16 Nov '15

16 Nov '15

> Christian Liendo wrote: > I went the previous Sat to see it only to find out it > was this past Sat. The museum Web page says it's an ongoing exhibit. What did you see on exhibit? The Web page shows only four photos. And by the way: those "New York" history photos represent Bell Labs (NJ) and Eniac (PA). So the exhibit likely represents work done in in the region. Wonder how far north they'll go? Herb -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net

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Re: [vcf-midatlantic] Festivus food thread: Who's bringing what?
by VAXman＠tmesis.org 16 Nov '15

16 Nov '15

David Riley via vcf-midatlantic writes: >On Nov 12, 2015, at 4:41 PM, Evan Koblentz via vcf-midatlantic = ><vcf-midatlantic(a)lists.vintagecomputerfederation.org> wrote: > >> Ps. OMARC is loaning us their grill. Someone should bring a full = >propane tank. > >I'll do that. I'll also be glad to bring pre-cooked pasta and a camp = >stove if someone else does the sauce; that worked well last year despite >= the spill. > >I'll be bringing some homebrew; I have a winter warmer that's come out = >pretty well that I can bring at least 12 of (maybe a case). Probably = >not enough to stave off Brian bringing the good black stuff. :-) Evan, I wasn't planning to lug the Guinness to Festivus. I won't be staying the evening which would not be a problem because I've left the kit there in the past and I retrieved it the next day. However, there's a rocket launch on that Sunday, so I won't be able to pick up the kit on Sunday.

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Apple IIe Voltmeter
by Herb Johnson 16 Nov '15

16 Nov '15

> [I had no way] to precisely measure current. My other bench meters are analog, > lowish impedance, and not precise enough to measure voltage drop > across a small-value resistor. Additionally, my Simpson 260 and > Simpson 160 meters don't agree on the 100 mA scales -- > I believe the Simpson 160 is correct, but needed a way to figure out. My experience is that digital voltmeters put too much current load on a circuit, when measuring DC current at tens of mA. Put another way: they have significant series resistance and change the circuit, and so change the current. Your A/D technology also puts a load on the circuit, you can read off the schematic or parts to determine that. But I found my Simpson 260 and other analog meters, put LESS load because they generally use 50uA movements (hence 20,000 ohms per volt, do the math). As to "figuring out the accuracy".....create a 10mA circuit from an accurately-measured battery and an accurately-measured resistor. Say 5V and 500 ohms, or whatever - the DVM can measure those fine, other resistors give other current sources, and math gives you the exact current. Many batteries can generally supply 10mA stable for minutes and hours or more, and your DVM can monitor their voltage anyway. Then make those circuits with the Simpsons and recalibrate the scales, and create conversion factors (or fitness for use choice) for each meter AND for each scale. YOu can use the same apparatus to calibrate your Apple II "meter". I prefer analog meters when making "runs" of comparative measurements. It's easy to see if one reading is "more" or "less" than another, the needle is literally in different positions. I've found variations in current measurements among several Simpson 260 meters (and among their scales) I've acquired. My guess is that some of the shunts were "cooked" by excessive current, or corroded by time and tide. I have not yet gone to the trouble of diagnosing them, I simply use the meters that have the best readings through the procedures noted. They are cheap today. Why? Given the "digital is better" bias these days, only a few people call out the Simpson 260 as a valued instrument - Dave McGuire for instance, in that email list we used to use. Jonathan, if you determine a cause for your analog meter's apparent errors, let me know. Herb Johnson old-school -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com

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Re: [vcf-midatlantic] [midatlanticretro] New York Historical Society : Silicon City: Computer History Made in New York
by Evan Koblentz 16 Nov '15

16 Nov '15

> https://www.nyhistory.org/exhibitions/silicon-city-computer-history-made-ne… > > They sent me an invitation to represent our group. Crap. I forgot to attend the ceremony last week.

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Re: [vcf-midatlantic] Festivus food thread: Who's bringing what?
by VAXman＠tmesis.org 16 Nov '15

16 Nov '15

Tony Bogan via vcf-midatlantic writes: >I thought the same thing! But I don't have a jolt cola or Mountain Dew >dispe= nser and also figured some might bring some family members during >the day :-= )= Start 'em young! ;) FWIW, when I did a computer security gig for M&M Mars many years back, one of the M&Ms remarked that he was surprised that my lunch didn't consist of Jolt cola and Twinkies. Yet another stupid Hollywood induced stereotyping of computer hackers.

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Re: [vcf-midatlantic] Festivus food thread: Who's bringing what?
by VAXman＠tmesis.org 16 Nov '15

16 Nov '15

Tony Bogan via vcf-midatlantic writes: >M > >Sent from my iPhone > >On Nov 15, 2015, at 9:36 PM, Evan Koblentz via vcf-midatlantic ><vcf-midatlan= tic(a)lists.vintagecomputerfederation.org> wrote: > >>>>> VCF will provide: burgers, beef hot dogs, rolls, common toppings, >commo= n >>>> snacks (chips, pretzels, etc), soft drinks, bottled water >>>>>=20 >>>> Guesstimated attendance is three dozen nerds... >>> Evan: >tray of soft pretzels >>> Corey L., via Kelly: beer >>> Vaxman: pork >ribs >>> Neil: Fudge Nut Brownies, Apple Cider Doughnuts > >> Tony: >Brownies, cookies, cupcakes, etc. > >> Chris F. Plastic utensils, >napkins >=20 >=20 > We still need volunteers to bring: > - paper or >plastic plates > - cold drink cups, styrofoam coffee cups > - coffee, >machine, cream, sugar, stir-ers, etc. > - any other appetizers / sides / >entrees beside red meat > - any other desserts / snacks > - Be creative: >anything else??? > >I can bring styrofoam plates, coffee, machines, (2 - 55 cup machines, >one fo= r regular and one for decaf) styrofoam cups for coffee too. Have >those in sp= ades for the boats. Coffee fixins' can be someone else's >domain :-) (especia= lly since I don't drink coffee!) Tony= Decaf? For computer geeks? :)

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Re: [vcf-midatlantic] Apple IIe Voltmeter
by tom.hornberger＠verizon.net 16 Nov '15

16 Nov '15

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Museum Report
by Jeffrey Brace 16 Nov '15

16 Nov '15

Doug Crawford was docent today at the museum. 4 pairs of adults came through today.

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hoodie order is placed
by Evan Koblentz 16 Nov '15

16 Nov '15

Thanks for playing. :)

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When exactly is the Festivus celebration?
by William Dudley 15 Nov '15

15 Nov '15

for those of use new to this. Thanks, Bill Dudley www.dudley.nu This email is free of malware because (to a first approximation) I run Linux.

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PDP 11/35 in Mahwah NJ on EBay
by Kelly Leavitt 14 Nov '15

14 Nov '15

Not what I collect, but some may be interested. I can probably arrange pickup and short term storage if needed. http://www.ebay.com/itm/191737673720 Kelly

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Apple IIe on eBay - I can pick up locally if anyone is interested.
by Chris Fala 13 Nov '15

13 Nov '15

http://www.ebay.com/itm/151877421051

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Re: [vcf-midatlantic] PDP 11/35 in Mahwah NJ on EBay
by Brian L. Stuart 13 Nov '15

13 Nov '15

On Fri, 11/13/15, william degnan wrote: > On Fri, Nov 13, 2015 at 1:43 PM, Kelly Leavitt wrote: > >> Not what I collect, but some may be interested. >> >> I can probably arrange pickup and short term storage if needed. >> >> http://www.ebay.com/itm/191737673720 > > Looks complete! 32K Core Parity RAM I'm pretty sure it'll end up going for more than I can justify, but just in case, I've got it in my watch list. Not to worry though, I certainly don't intend to get into a bidding war with any of you fine folks. BLS

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Apple IIe Voltmeter
by Systems Glitch 13 Nov '15

13 Nov '15

VC Forums thread: http://www.vintage-computer.com/vcforum/showthread.php?49958-Big-Voltmeter-… I discovered my Fluke 8000A no longer measures current (fuse is fine) and realized that meant I had no way to precisely measure current. My other bench meters are analog, lowish impedance, and not precise enough to measure voltage drop across a small-value resistor. Additionally, my Simpson 260 and Simpson 160 meters don't agree on the 100 mA scales -- I believe the Simpson 160 is correct, but needed a way to figure out. I thought about using the ADC on a PIC to do the conversion, but my PIC dev stuff is still packed from the move. My Apple IIe isn't though, and I do have an ADC card for it -- the Interactive Microware ADALAB. Someone recently uploaded a manual for it! The IIe also has floating point BASIC, which makes converting ADC to voltage easy with no lookup table, and lets me adjust parameters on the fly -- switching sense resistor values, for example. Anyway, I had fun getting the ADALAB tested, and ended up calibrating it with a quick n dirty BASIC program (listing in the VC Forums post) and a LM103 2.7V reference. Good enough to show it works! After getting that BASIC extension typed in and making sure it worked, I made extra-sure to SAVE it to disk and avoid having to type it again! Thanks, Jonathan

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OT: Guy has his son play though video games in chrnological order.
by Kelly Leavitt 13 Nov '15

13 Nov '15

A fun read. A guy has his son play through some of the classic games. Don't recall seeing this before, but it is from a year ago. Probably some errors and oversights but a fun read. https://medium.com/message/playing-with-my-son-e5226ff0a7c3 Now I must... ...mambo dogface to the banana patch. Kelly

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Last chance: Hoodie deadline 5pm ET today
by Evan Koblentz 13 Nov '15

13 Nov '15

Final reminder. ========================== We are ready to take orders for the Federation hoodies. They'll be black with front pockets and (obviously) hoods. Design will be our new logo on the front. Only change is the keys won't have the gray shadow, because that would be a third color and too expensive. Speaking of prices: Small through XL = $20, 2XL = $25, 3XL = $30. All are men's sizes. Kids/womens/or anything bigger than 3XL not available at this time. ***** VERY IMPORTANT: ***** - All orders MUST be placed by next Friday (Nov. 13) at 5PM ET. At that point I'll email our order to the shirt company. Procrastinators will have to wait for another batch some other time. - You must prepay. Hoodies are too expensive for us to lay out the money and chase you down for it later. Acceptable methods of payment are through PayPal (hoodies(a)vintagecomputerfederation.org) or send a check to Vintage Computer Federation. Our address is P.O. Box 417, Eatontown, NJ, 07724. - Put the sizes and quantities you want into the PayPal comments box or the check memo field. - DO NOT say "I'll take size XYZ" in email (to me, the list, or wherever) and expect us to fill that order. Follow instructions above.

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