April 2018 - vcf-midatlantic

Head align Tape
by Duane Craps 15 Jul '18

15 Jul '18

>>> 7 track or 9 track? The Univacs are pretty old even for "vintage". Head alignment tapes are not track specific. They have one track the width of the tape and are used to adjust time delays to time align the bits coming off the read head when reading the alignment tape. Then a "scratch tape" is used while writing all ones to adjust the write delays while looking at the read amps. We used the same alignment tape for 7 and 9 track units. Duane On 6/17/2017 11:40 AM, Dave McGuire via vcf-midatlantic wrote: > 7 track or 9 track? The Univacs are pretty old even for "vintage". On 6/17/2017 11:40 AM, Dave McGuire via vcf-midatlantic wrote: > On 06/17/2017 11:37 AM, Herb Johnson via vcf-midatlantic wrote: >>> UNIVAC 1540 Magnetic Tape Unit...I wonder if anyone has a 800 BPI, >>> NRZ Master Head Alignment Tape (skew tape) to donate to VCF. >> 7 track or 9 track? The Univacs are pretty old even for "vintage". >> >> Also, as Dave McGuire noted, a lightly-used tape from a known-good drive >> will be useful. In the floppy-disk world, I use several diskettes each >> from a known good drive to validate "alignment". > That wasn't me. But yes, that can be useful for rough validation. > >> Seems to me, there's likely several boxes of mag-tapes in the inventory. > Yes, I brought a few boxes several years ago. > > -Dave > v

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Bill Loguidice's Collection Auction Date 5/31 Edison NJ
by Bill Degnan 01 Jun '18

01 Jun '18

Bill Loguidice's Collection Auction Date 5/31 Edison NJ https://www.auctionzip.com/cgi-bin/auctionview.cgi?lid=3023450

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Who's near Aston PA?
by Evan Koblentz 14 May '18

14 May '18

We need three boxes of (important) magazines picked up in Aston PA and delivered to the museum. ________________________________ Evan Koblentz, executive director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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ANNOUNCE: VCF East XIII 8085 Single Board Computer
by systems_glitch 12 May '18

12 May '18

Some of you may have noticed that I've been extra busy/slow to reply lately. It's not just because of taxes :) This is on my bench: http://i.imgur.com/TppyO2Mh.jpg We got together on the idea of a special edition vintage computer project for VCF East last year, but there wasn't enough time between when someone mentioned the idea and the event to actually get it done. This year, I've revised my 8085 SBC design into a larger, more full-featured board as seen above. Specs as follows: * 8085 CPU * 64K Static RAM * 32K ROM available in 4K pages * Autoboot/ROM switchout circuit * 8251A USART for console port * DS1233 EconoReset * Baud rates from 300 - 38400, baud clock independent of CPU clock * GlitchBus expansion header * Single 5V power supply The board is 8x5 inches, the GlitchBus expansion stacking area provides for a 4x5 inch board. Currently I've got the prototype version running GWMON, my ROM monitor, from Ferroelectric RAM in the ROM socket. The goal is to have a customized monitor and fully functional BASIC by VCF East. This is also the first board to commit to a GlitchBus pinout/layout -- several of us have been working together offline and through IRC to get it nailed down. Eventually, you'll be able to add a storage controller (CF, floppy, etc.) via GlitchBus and boot/run CP/M! The ROM can be switched out under software control, so the full 64K of RAM will be available to user programs. The board also supports FeRAM, so it's possible to have a core-like setup for main memory. If you use FeRAM or an EEPROM in the ROM socket, the board can update its own firmware. This revision is going to be released at VCF East XIII and is a special edition that will probably be limited to the show. We'll be doing an event-long workshop to build and test the SBC at InfoAge during VCF East, just like we did with the XT-IDE and Apple II prototyping workshop last year. If you choose to assemble your board at VCF East, you'll leave with a 100% tested and working 8085 SBC. I may bring a very few CRT terminals to make available to builders of the 8085 SBC. Evan got me a high-res PNG version of the VCFed logo, which I was able to work into a copper-and-silkscreen graphic for the PC board: http://i.imgur.com/H6iJnXIh.jpg I haven't nailed down a price for parts kits yet -- that will be forthcoming. Thanks, Jonathan

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A few workshop notes
by Herb Johnson 01 May '18

01 May '18

I was able to come out to the workshop on Sunday, and work on an unusual computer I obtained. It's a Motorola EXORset 30. It's a 6809 development system running an XDOS OS on floppy, and supported by Motorola's EXORbus bussed backplane. It came up without a lot of fuss. It needed some careful AC power conditioning to the power electrolytics. http://www.retrotechnology.com/restore/exorset.html I gave some support to Adam, who was able to operate his SGI Indigo computer for the first time, thanks to a keyboard and mouse I provided. I chatted with several people attending, providing sage wisdom about problems with RAM, switching speeds of diodes, pressure rollers on tape drives. I removed some rust from a couple of dot-matrix printers, and was surprised to find they could still print! Thanks to Jeff Galinat, who leant me AC cables and a 360K diskette; and to Jeff Brace for his support of and at the Workshop. Of course, I learned a lot about how my friends were diagnosing these issues. The depth of talent on site Sunday was amazing. It's rare and informative, to discuss 3-volt negative logic and the switching speeds of diodes at one point, then the problems of aged hard-rubber rollers at the next moment. I learned more about the early history of Apple II products. I got under the hood of some early Commodore PET's to see the less-than-industrial designs they produced early on. Any of these repair and preparation activities could be discussed at length. And it's a pleasure to see what the Museum's UNIVAC is able to do, even as more work is in progress. To think that other shipboard computers like that, were operating at sea in the late 1970's is astounding. Then to have one operational today, that's a great gift. That's also true of the PDP-8 "straight-eight", which was under repair at the diode level this weekend. And it's good to see my friends again, see and hear about them and their work and history with vintage computing. Even the weather was cooperative. Herb Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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A few workshop notes
by Evan Koblentz 30 Apr '18

30 Apr '18

Good workshop this time around! Thanks to Jeff for organizing and everyone who attended. A few notes: - Special thanks to Ian, Jason P., Rich, Eric, Jeff J., Jeff B., Matt K., Laura, Martin (remotely), and Adam for all working on VCFed things. - Special thanks to just about everybody who was there Saturday and helped with unloading the IBM System/34. Darn good thing that IA owns a forklift and the military vehicle group guys were there to operate it! That's the right tool for the job, and it sure made easy/short work of unloading the minicomputer. - Last thing I did before leaving today was install the front trim panels on the UNIVAC pallets. Now they look like display platforms instead of forklift pallets: https://tinyurl.com/yctdlkfl. ________________________________ Evan Koblentz, executive director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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stumbled upon this TRS-80 thingy
by W2HX 30 Apr '18

30 Apr '18

https://bindable.com/api? looks like a model 4, but with some kind of blanking panel where the drives would live. I wonder if this was an actual version, maybe used in training or a dumb terminal? Or maybe someone just made up a panel. Looks nice :)

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Workshop tomorrow breakfast
by Jeffrey Brace 28 Apr '18

28 Apr '18

9am Princess Maria Diner, then back to workshop by 10:30.

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road signs, construction on I-95/I-295 near Trenton NJ
by Herb Johnson 28 Apr '18

28 Apr '18

For those traveling by car or truck on I-95 - I-295 around Trenton NJ. About the "loop" around Trenton, from the PA border, across US-1, to I-195 east/west (a major route to VCFed facilities at Infoage / Wall NJ). There's a signage and exit-number change on that loop. The entire loop is now signed "I-295", from the PA-NJ border to I-195. Formerly the NJ segment from the Scudders Falls bridge between PA and NJ, to US-1, was called "I-95". So your GPS maps may/may not show, and your eyeballs will see, signs which look a little different. I live in that area. There's also changes now and in years to come, at the PA Turnpike (I-276) and how it connects to the NJ Turnpike and to I-95 in PA. I don't follow that in detail and don't use those routes. But in several years, that Scudders Falls bridge will be replaced and become a toll bridge. Construction is happening there NOW and it may slow down traffic and line the road with blinky-light barriers. Old folks like me, who use paper maps and navigate by signs and eyeballs, not some digital GPS voice, pay attention to this stuff. Please, no snarky remarks, I'm trying to do my driving friends a favor here, not expose myself to ridicule. Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Two incoming artifacts tomorrow
by Evan Koblentz 28 Apr '18

28 Apr '18

Tomorrow's workshop attendees will get to see two new artifacts if things go according to plan: the NeXT Cube (morning) and a minicomputer (afternoon or evening, depends on the person driving it down to us from Boston).

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