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dkerfoot

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About dkerfoot

  • Birthday 10/14/1965

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    Holland, MI

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  1. Not aiming for any politics, just some sad 8-bit news: https://www.npr.org/2022/03/29/1088680989/a-retro-computer-museum-in-mariupol-beloved-by-children-was-attacked-by-russia
  2. My high school computer lab had I think six 400s and four 800's that were somehow "networked" to a stack of four of 810s (I don't remember the details). We'd fight over who got to use the 800s, but the 400s weren't that bad to type on if you were a bad typist anyway. Our teacher always made us write out our programs on paper first and only when he approved it did we get to type it in and try it. We worked in teams of three and I remember him "rewarding" teams that came up with the best solutions by letting them use one of the 800s to type it in. I personally think the video showing the mom wiping the ice cream off the 400 is an example of marketing recasting a cost reduction as a feature. Yeah sure, it would be easier to wipe ice cream off of a 400 keyboard, but the membrane keyboard was originally selected for lower cost.
  3. I don't think it is. No "data sound" on startup. No sound if a cart is loaded. No typing sound.
  4. Thanks for the help. I am slow to reply because I couldn't find my old logic probe, so I had to order one. Reset (pin 40) goes from low to high when turned on. Pins 9-20 and 22-33 all toggle at various rates. 5.02 VDC on pin 8 of Sally, Pin 21 Antic, Pin 27 GTIA, Pin 17 Pokey, Pin 20 PIA. Swapped out UAV, no change. Do you suggest checking power on the other chips too? Any other suggestions?
  5. Agree it isn't likely UAV but I may swap it too just to be certain. Yes swapped PS. Actually used the same one on both machines, yet swapped it too just to be 100%. Don't disagree that one chip at a time is better, but when time is limited... I was up until 1:30 AM working on the thing as it was... ALL chips swapped - no exceptions. ALL. Because the three wires used in this RAM upgrade are all soldered to the shoulders of the pins on the chips, the entire thing can be moved from machine to machine. In other words, if I had a cold solder joint, it would have moved from bad machine to good along with the chips. I'll have a closer look at the CPU and Antic. I do very much appreciate the help.
  6. ALL chips were swapped - No exceptions. No resistors for any of the upgrades. Also, for clarity, the upgrades have all been in place for six months or more and it was working fine, until yesterday when it stopped. I should add that none of the chips get hot.
  7. I have two basically identical 600XLs. Both Rev A, both have the 3-wire 64K memory upgrade and both have UAV Rev D. Oh, they both have Hias' 1.30 high speed ROM too. (The perfect compact combination for anyone that isn't into demos or actually doing a bunch of typing, IMO) One suddenly has a black screen on boot. Power LED lights and the TV goes from blue (unconnected default) to black. I never hear the "data sound" of basic loading. Since I have another (and happily the RAM upgrade I did doesn't require soldering to the MB) I have been able to swap all chips between the two units, 3 or 4 at a time. The bad unit remains bad and the good unit remains good. There is no apparent damage to the MB and the contacts all look good - nothing bent, apparent corrosion, etc. I did reseat each chip a couple of times. No joy. Any ideas on what it could possibly be? I do have reasonably good electronic troubleshooting skills and tools (including an o'scope), but I don't know enough details about the circuits to know where to start or what to look for. Does the black screen point to any particular circuit? Any help would be much appreciated.
  8. The black plastic card-edge connector that is soldered to the motherboard. I could use the part itself, an old scrap motherboard or else 10-12 of the actual internal pins. I've got the tools and skills to desolder one from a scrap MB. History: I had a keyboard growing increasingly flaky, but everything tested good. In fact, swapping the keyboard, flat-cable and little circuit board with all the resisters on it showed the problem was with the motherboard. Pushing the connector one way or another would make the problem better or worse, but never completely working. Turns out the connector was not solidly flush to the motherboard and over the years, a few of the pins had broken off underneath it. I'd like to keep the socketed 600XL motherboard because I've already installed 64k RAM, UAV and Hias 1.3 patched OS on it. Hopefully somebody has the part available in some fashion so that I can put this Atari back to good use! Also, I am selling off most of my collection (hopeful to keep this 600XL if I can find the part though). I've sold off a couple systems. Currently I have a variety of peripherals and books and game carts. I'll eventually be listing more systems, etc... https://www.ebay.com/sch/laketech/m.html
  9. Resurrecting an old post. I have a ctirad RAM320-XL with case and pigtail. $50 shipped within the US. -Doug
  10. Having finally installed new OS ROMs with Hias' 1.30 patch, I've been able to test a bunch of different scenarios After much experimentation with the Raspberry Pi Zero W, I have found I can connect via version 0.8.7 of AspeQt at a reliable 57,600. This matches what I can do over an old built-in (DE9) SIO2PC on my 800XL connected to an old desktop PC with a serial port. With RespeQt 4, I can reliably connect at 128,000 (divisor 0) over SIO2PC-USB. This matches what I see from my new laptop connected over the same device. So, while the serial ports are certainly usable, USB is better than twice as fast. Additionally, the Pi doesn't max out the CPU while querying the USB port like it does with the serial port and you don't need to rejigger the bluetooth settings. So, USB seems like the obvious way to go.
  11. To follow up on this discussion in case someone is reading this later: I had two identical Atari 600XLs, except one had C89 and C90 removed, the other had them still in place. Both have 64k and UAV video. With stock OS, I could never get anything but 19,200. Installed new EPROMs of XL OS patched with Hias v1.30. Using RespeQt 4 to load International Karate over Sloopy's SIO2PC-USB. The one with C89, C90 still in place maxed out at 88k, while the other ran 125k no problem. Clipped out C89, C90 from the 2nd 600XL and it now also loads at 125k. Needless to say, I am very happy with this simple (once you know what needs to be done) upgrade!
  12. https://www.cnet.com/news/atari-yes-that-atari-teases-new-game-console-ahead-of-e3/
  13. I have a bad keyboard in need of replacement. You have an old 600XL/800XL parts machine with a fully functioning keyboard. Let's talk.
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