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Everything posted by JGRAHAM2

  1. Need to clean it up, but it works 100%! That little board to the left was to press on the four wires from the Mosaic board to the back of the cart port. I didn’t like that so I soldered them.
  2. You are right. I was following the text when I soldered it and looked at the pictures when I checked it.
  3. I found in another post on this site that you must use external power on S-Drive Max or FujiNet. I have both on the S Max and sure enough, it works!
  4. So, after rechecking my soldering I confirmed the problem to be between the soldering iron and the chair. I had soldered wire “7” to pin 9 of the RAM chip instead of pin 8. Now it works with BASIC and other carts. It no longer works with the UNO cart. It also will not boot off of S-Drive Max OR FujiNet. PIA or Pokey?
  5. Here it is Mosaic 48K RAM Upgrade.pdf
  6. Thanks, I’ve never seen that before. I know the Mosaic documentation refers to it as a capacitor.
  7. I have it working... kind of. Comes up as a black screen. If I hit reset, it will run a cartridge. It will even run the Uno cart. If I select a cart on the menu, it will start after another reset. Buck Rodgers will start without reset. Basic will produce a Ready prompt and will take input, but freezes after one line. It did all of this after I rotated the RAM chips. I believe it’s just a bad chip.
  8. One thing I notice is one of the solder points goes to a diode on this board. It is a resister on my other 16K board. (C523)
  9. I appreciate the offer, but I have installed the Mosaic and right now, it isn’t working right. I’ll be troubleshooting it tonight.
  10. B-Key was one of the things I really wanted in the early 80s. I never really got serious about programming until I got my 800XL. I bought this with the keyboard for nostalgic reasons. I actually bought my original machine because I thought the keyboard was futuristic looking and cool.
  11. It requires some cutting traces, removing capacitors, soldering 6 points, replacing RAM, plugging in a board in place of an ic and connecting to the motherboard with a press on connector. I did it and it partially works. I get a black screen. On reset I get BASIC, but PRINT FRE(0) gives the wrong free memory 39,000+ instead of 37,000+ and it freezes. List produces zeros. Star Raiders works, but other carts do not. I think I have some bad RAM. I’ll try other chips and recheck my wiring tomorrow.
  12. Yes, I’ll upload here sometime this week.
  13. I’m talking about the Mosaic 48k upgrade. I think someone bought it back in the day and after reading the instructions, they decided not to try it.
  14. I’ve got 3 others with the old keyboard and a set of extra boards, so I’m good there.
  15. What do you think? Install in my B-Key 400 or keep as it is?
  16. Are the exact pickup points for the U1MB documented somewhere?
  17. This is an old post, but who has tried this upgrade?
  18. I have 2 of these I’m working on. They are dirty, but for the most part are in working order. The issue with both was the little micro switches under the Start, Option, Select, etc. I tried contact cleaner. Don’t do that. It quite effectively stopped all from working. Taking them apart, they are about as cheap of a device they could source. A rubber cup with a conductive coating shorting 2 tiny pads. I was able to resurrect them using CaiKote 44, but lesson learned. Try one first. I tried using a pencil to restore the conductive layer, but no deal. I had the CaiKote to fix a C128 keyboard. Anyway, on to my question. See the picture. Have you seen a XEGS case top warp like this? Any suggestions on straightening it? I have another and it is not like this. Also, I think the composite video out of this computer is pretty good, so I use my UAV for another one.
  19. Too late for that unfortunately. I will reinforce it and then use a tap perhaps. Thanks.
  20. This is what I’ve done so far, plus glued the ones holding one side of the keyboard. More will have to be done to reinforce it. I’ll use some of the suggestions above.
  21. It happened when they shipped it to me. I’ve had a couple vintage computers damaged in shipment, most of the time due to poor packaging and sometimes due to poor handling.
  22. I actually have 2 800s. Since I am installing an Incognito in this one, I will probably switch cases and defer fixing this one until later. I have about 6 projects going right now, most waiting on parts to come in.
  23. I just took apart an 800 that I bought some time ago. I noticed a little chip out of the case back then, but when I took it apart, I found it is much worse. Any ideas on what to do about this? These cases must be like porcelain. Other than that, I found that it has an Axlon 128K RAMDISK, which is kind of cool.
  24. This was the DMA chip. I replaced it with one from an old 520ST and it is functional again. Thanks everyone.
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