JGRAHAM2 Posted February 16, 2021 Author Share Posted February 16, 2021 (edited) 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. Edited February 16, 2021 by JGRAHAM2 Quote Link to comment Share on other sites More sharing options...
ClausB Posted February 17, 2021 Share Posted February 17, 2021 5 hours ago, JGRAHAM2 said: 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) C523 is a capacitor. Atari used caps which look like diodes or resistors. Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 17, 2021 Author Share Posted February 17, 2021 12 hours ago, ClausB said: C523 is a capacitor. Atari used caps which look like diodes or resistors. Thanks, I’ve never seen that before. I know the Mosaic documentation refers to it as a capacitor. Quote Link to comment Share on other sites More sharing options...
ClausB Posted February 17, 2021 Share Posted February 17, 2021 On 2/15/2021 at 9:17 PM, JGRAHAM2 said: Yes, I’ll upload here sometime this week. I look forward to the instructions but in the mean time let me guess: The green board plugs into the socket where the LS10 chip is and the 4 blue wires go to board edge pins S and P, pin 1 of an LS158, and pin 9 of the RAM chips. Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 17, 2021 Author Share Posted February 17, 2021 On 2/15/2021 at 8:40 PM, Allan said: @JGRAHAM2 Could you possible scan the Mosaic manual? Here it is Mosaic 48K RAM Upgrade.pdf 3 Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 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? Quote Link to comment Share on other sites More sharing options...
ClausB Posted February 18, 2021 Share Posted February 18, 2021 Wire 7 should go to RAM pin 9, not 8. The instruction text is wrong but the photo Fig 13 is correct. 1 Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 37 minutes ago, JGRAHAM2 said: 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? 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! Quote Link to comment Share on other sites More sharing options...
adam242 Posted February 18, 2021 Share Posted February 18, 2021 On 2/15/2021 at 4:57 PM, BillC said: Or the 48/52KB RAM card by @tf_hh, who also sells a replacement CPU card with integrated UAV. Bought both of those last year but I haven't gotten around to installing in one of my 400s. Some day... Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 39 minutes ago, ClausB said: Wire 7 should go to RAM pin 9, not 8. The instruction text is wrong but the photo Fig 13 is correct. You are right. I was following the text when I soldered it and looked at the pictures when I checked it. Quote Link to comment Share on other sites More sharing options...
bfollowell Posted February 18, 2021 Share Posted February 18, 2021 On 2/15/2021 at 7:11 AM, JGRAHAM2 said: What do you think? Install in my B-Key 400 or keep as it is? There are easier, and cheaper memory upgrade options for our 8-bits these days, even the 400/800 machines. If it were me, I think I'd go for a more modern upgrade, and save that upgrade as a collector's piece. That's just me though. Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 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 1 Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 1 minute ago, JGRAHAM2 said: 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. By the way, the keyboard was made by Cherry. I was surprised at that. Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 21 minutes ago, bfollowell said: There are easier, and cheaper memory upgrade options for our 8-bits these days, even the 400/800 machines. If it were me, I think I'd go for a more modern upgrade, and save that upgrade as a collector's piece. That's just me though. I can see your point, but this was what I wanted to do on my first computer in 1982. I tried to buy the keyboard, but couldn’t find one. I couldn’t afford the memory upgrade. It is a nostalgic thing. Quote Link to comment Share on other sites More sharing options...
bfollowell Posted February 18, 2021 Share Posted February 18, 2021 12 minutes ago, JGRAHAM2 said: I can see your point, but this was what I wanted to do on my first computer in 1982. I tried to buy the keyboard, but couldn’t find one. I couldn’t afford the memory upgrade. It is a nostalgic thing. OK, I can definitely get that then. Sometimes the heart wants what the heart wants. If that's the case, why the post? Heck, it doesn't matter what any of us think. Do whatever you want that is going to make you happy and everyone else's opinion be damned. Go for it! I'm glad you're finally getting to fulfill that 1982 dream. It only took 38 years! 2 Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 18, 2021 Author Share Posted February 18, 2021 8 hours ago, bfollowell said: OK, I can definitely get that then. Sometimes the heart wants what the heart wants. If that's the case, why the post? Heck, it doesn't matter what any of us think. Do whatever you want that is going to make you happy and everyone else's opinion be damned. Go for it! I'm glad you're finally getting to fulfill that 1982 dream. It only took 38 years! I like the discussion. There is a story to my first 400. I bought it at a Montgomery Wards warehouse store. I learned BASIC on the machine and how to fix it when I broke it. (Actually, a bar code reader called Oscar broke the SIO.) It got me started in an IT career. Now I work in the building where I bought it. 4 1 Quote Link to comment Share on other sites More sharing options...
Faicuai Posted February 19, 2021 Share Posted February 19, 2021 15 hours ago, JGRAHAM2 said: It got me started in an IT career. Now I work in the building where I bought it. That is SO cool! Thanks for sharing that story... My first one ever was a 400, too.... Don't have too much love for that particular machine... but just love the sweet memories... If Incognito/400 ever shows up, I may reconsider my piosition... ;-) Enjoy that upgrade... Mine was an AXLON 32KB, which was much simpler to install, though... but still no 48KB ! 8-( Quote Link to comment Share on other sites More sharing options...
+Allan Posted February 19, 2021 Share Posted February 19, 2021 On 2/17/2021 at 5:44 PM, JGRAHAM2 said: Here it is Mosaic 48K RAM Upgrade.pdf 12.05 MB · 10 downloads Thank you. Quote Link to comment Share on other sites More sharing options...
Mark2008 Posted February 19, 2021 Share Posted February 19, 2021 Nice, I like it. Now take it apart and do it again. This time, blind folded. Quote Link to comment Share on other sites More sharing options...
JGRAHAM2 Posted February 19, 2021 Author Share Posted February 19, 2021 6 hours ago, Mark2008 said: Nice, I like it. Now take it apart and do it again. This time, blind folded. I probably could now! Quote Link to comment Share on other sites More sharing options...
ClausB Posted February 22, 2021 Share Posted February 22, 2021 My best guess as to the circuit on the "converter board": 1 Quote Link to comment Share on other sites More sharing options...
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