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8085 SBC rev 4 Mini Documentation
by Jonathan Chapman 06 May '24

06 May '24

All, Finally got the documentation package for the 8085 SBC rev 4 Mini (one of this year's VCF East kits) nailed down: http://filedump.glitchwrks.com/projects/gw-8085sbc-4m/ The above link includes the manual, schematics, GAL equations, and Flash chip image. If you weren't at the workshop, you can buy the bare board, kit, or fully assembled SBC on Tindie: https://www.tindie.com/products/34563/ Thanks, Jonathan

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FTGH: bad DSDD 3.5" disks
by Jonathan Sturges 05 May '24

05 May '24

To bolster my stock of DSDD 3.5" floppies, I recently bought a lot on eBay. But it included roughly 40 disks that won't format cleanly. Would anyone like these? They don't seem to be good for data but maybe an art or craft use? Free shipping to any takers in CONUS. -Jonathan

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Old computer I can learn to repair?
by Herbert Johnson 04 May '24

04 May '24

Caution: lecture. Reading time long, skip if impatient. a real question was asked. Sorry. How to use an oscilloscope, is a tough question now in 2024. It's an experience few people have today, that might have an interest in how some computer-thing works when broken (or not). So why do some people make it *hard*? ;) Traditional responses to "how to use an oscilloscope", is 1) to learn the instrument thoroughly, 2) be sure it's accurate 3) use it for designated purposes like research, repair. 4) oops, better learn digital logic and microprocessor signals too. (whoa, that's so complicated). That's because, computers and oscilloscopes were once expensive things, used by people with detailed knowledge of signals they show and how those signals are produced, and why. That's college-level tech, from the days of simple computers and simple electronics. That's my era. But oscilloscopes now, are just a thing like other electronic things. Old and cheap, new and cheap, buy and try and figure it out. So, I don't think the old-school approach is gonna work. So here's my old-guy approach with try-it in mind. YOu bought a 'scope. Grab anything you have that has a circuit board that's battery powered. Figure out where "ground" is, clip the ground lead there. Now use your scope probe, put it on parts of the circuit. Wadda see on the scope? HOwever: learn what it means to "ground" things and avoid "AC shocks". That's why I suggest battery-powered stuff first. If you don't see anything on your scope, look through whatever oscilloscope manual you can find. The manual for your scope will help BUT it's like "here's how all the knobs work" and not too useful for "why do that?". But look for advice and how-tos. It would not hurt to find old "how to use your oscilloscope books", but there are PDF's of those. also, find some info on whatever you are probing. Know what a schematic is? You'll find out! HOpe you find some for whatever you are messing with. Do that awhile, on different things. Read, test, probe. Now you have experience. Get more information based on what you KNOW now, and then what you want to know. If you want to repair something in particular (computers)? Grab one, any thrift store, your friend's closets and attics, whatever local. Or USB hubs or routers. *DOn't mess with CRT monitors or LCD's or TV's yet. YOu could hurt yourself seriously. Please avoid for now.* Look inside. Now what? The chips are small, the leads smaller, and nobody tells you (or me) what those signals and chips mean. It's a dead end (for most of us) to use an oscilloscope on modern computers. Same applies for Arduinos and Rasp Pi's, other than looking at signals your program produces, where you know (or should) what signals look like and why. This is not your fault. The old 8-bit computers? The simplest old/new vintage computers are little single-boards based on 8-bit processors like those in the C128, Apple II, and other 1980 computers. There's lots of sub-$100 kits for those, today, if you like building kits. The old processor data sheets, describe the signals. Look them up, to get some clues. They use "big" chips, big pins, not the little "surface mount" chips on today's devices, too small to poke at. See, you are learning stuff already, just reading this. I hope! Still, at some point, you'll have to do some homework on how vintage computers work at the chip IC level. That's what the oscilloscope tells you about. It's not your fault or the oscilloscope's. that's what it's supposed to do, the computers do what they are supposed to do. If the computer fails and some signals fail - how would you know failed from good signals? You gotta do your homework eventually. YOu'll break things, using your oscilloscope. Everyone does. Plan B if "all this stuff is too hard"? Well, that "how to use an oscilloscope kit" amounts to a AC to DC power supply running a "five fifty five" or 555 chip oscillator/timer. That's a very famous chip, whole books (not hard to read) about them. Simpler than a processor! A person, Forrest Mims, is an old guy who builds simple circuits, to do *real things*. He's done that for half a century! He's actually important for doing that. His circuits, are still simple. Look them up, see what you can do with computers or without, using simple circuits. Gotta start somewhere with circuits! YOu used to be able to buy breadboard "build 99 circuits" kits with power and a breadboard ready for use - then put chips in it, hook up wires to do things. that's a great learning opportunity. Check Ebay for those old breadboards, repairing them is fun too. https://www.retrotechnology.com/restore/breadbd.html There's several "hackerspace" type companies that still sell learning how-to electronic kits, some that use non-microprocessor "analog ICs" or "digital IC's". try some of those things. It's all online now of course, no local shops. There's actual hackerspaces, look for those near you if you are social and mobile. But the thing is, going with no knowledge is kind of intimidating. Some shops have beginner's days. Or go just to watch, not bug people with questions. Figure out the social scheme of the shop. It's all a process. It takes time, attention, desire and interest. It's a real thing, not a ten-minute thing, that's how such things go. That's the world that an oscilloscope can explore, but you point the probe not the oscilloscope, so you gotta know. I said, this was a real question. Regards Herb Johnson -- Herbert R. Johnson, New Jersey USA https://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net

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Vote for VCF's new bumper video - The Final Version is Here
by Herbert Johnson 04 May '24

04 May '24

You asked for opinions, got several. Here's mine. Several people of and around my era of now-vintage computing, don't like *any* music and many otherwise don't like noisy-sounds (but keyboard sounds are mostly not objectionable). That's my view also. The point (so I'm told) of the video, is the VCF brand. Not the history of Bell Labs or voice synth or sounds made by an Atari something. Keyclicks, those are so broad in history and so common, they draw attention and then are background. If you are gonna have a movie, and have sound, keyclicks do enough work not too much and not a thing-themselves. For those who crafted all this stuff, my apologies if they are disappointed in my responses. This is a five-second event, shall I write a thesis about it? It's *exactly* impressions, you have mine and what I can make of them. But thanks for the Daisy / Bell Labs callback. I did some homework on the subject, it's surprisingly important. And it's commentary on modern vs. historic responses to almost-human computer behavior. I got informed - but, I was distracted from the VCF brand accordingly. That's not your goal, right? Regards Herb -- Herbert R. Johnson, New Jersey USA https://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net

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Old computer I can learn to repair?
by Benjamin Krein 04 May '24

04 May '24

I just got my first ever oscilloscope (Zoyi ZT-703s) but I have a problem - I don't have any broken computers! :) Anyone have any old computers that are repairable they want to get rid of? Probably something 8-bit just because I'm an absolute beginner. I'm also thinking something more common just because resources will be easier to find. Here's my wish list but I won't look any gift horses in the mouth! 1. Commodore 128 2. Atari 400(xl)/600/800(xl) 3. Apple IIc(+) I've always wanted an Amiga (500) but I'm not sure if that's getting too complicated or not for the scope I got? I'm in the Philadelphia area. -- - Benjamin Krein

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Re: [vcf-midatlantic] Vote for VCF's new bumper video
by Bill Degnan 04 May '24

04 May '24

Why not just keep them all and make new ones as needed, always with the consistency of the "typing part"? The author of a given video can then choose from a stable of bumper videos, selecting the bumper that best matches the content? My vote is thus: One with typing only, and a library of versions built up over time with appropriate audio music and effects. Holiday-themed set, manufacturer set, famous computer sounds, advertising, etc. Bill Degnan On Sat, May 4, 2024, 6:49 AM Sentrytv via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > I agree with Jeff > Leave the video as is remove the audio . > > Mike > > Sent from: > My extremely complicated, hand held electronic device. > > > On May 4, 2024, at 1:01 AM, Jeff Galinat via vcf-midatlantic < > vcf-midatlantic(a)lists.vcfed.org> wrote: > > > > I would be fine with omitting the music. Just the logo with the typing > > works for me, but that was not an option. > > Regards, > > Jeff > > > >

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VCF Bumper to videos
by Jeffrey Brace 03 May '24

03 May '24

We had a volunteer create a bumper for our future VCF videos. What does everyone think? https://youtu.be/3c0F9bENQW4 Can anyone identify: 1) The computer starting up 2) The song 3) The keyboard making the clicking sounds? Take care! Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner VCF Mid-Atlantic Event Manager Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Re: [vcf-midatlantic] Altair @ 50, why front panels are popular
by Herbert Johnson 03 May '24

03 May '24

PYROMATE Digital P45AF Firing System Pyrotechnics Fireworks Displays Module eBay item number:135003938238 plastic suitcase, orange panel toggles/lights The Van Vliet’s Company (111) 100% positive US $2,500.00 BIN B/O “Used but in great condition. All features are working. Contact for any additional information.” Free Standard Shipping. Located in: Riverview, Florida -- Herbert R. Johnson, New Jersey USA https://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net

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Repair workshop who’s going?
by Jeffrey Brace 03 May '24

03 May '24

Let me know or sign up. Take care! Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner VCF Mid-Atlantic Event Manager Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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Big personal collection at home
by Jeffrey Brace 03 May '24

03 May '24

An editor at an architecture and design magazine asked if I could refer him to any collector that has a notably large vintage computing collection preferably in the NYC metro area. This is not a museum that he's looking for, but someone's private residence. If you have any ideas, then send me an email with the person's contact info and I will let him know. Thanks! Jeff Brace VCF National Board Member Chairman & Vice President Vintage Computer Festival East Showrunner VCF Mid-Atlantic Event Manager Vintage Computer Federation is a 501c3 charity https://vcfed.org/ <http://www.vcfed.org/> jeffrey(a)vcfed.org

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