Atari 64K Memory Card (Atari 64KMR) for 1090 xl expansion system

[ClausB]

Thanks, that confirms it. If you want 256K, wire U20 pin 1 to ground and insert a 74LS153 into the socket at U20.

 

BTW, this isn't an attempt to modify the 1066 into what it's not. Clearly the original designers had 256K in mind. They got most of the way there and then backed off for some reason.

 

The date on the original schematic is May or June, 1984, months before I designed the 256K upgrade for the 800XL which appeared in BYTE a year later.

Edited September 17, 2021 by ClausB

[kenames99]

would you give me permission to put your updated schematic into the repo on my github? this is a very nice update to the design and will integrated in the near future but I will need your permission for that as well. thank you for your contributions.

 

Ken

 

[ClausB]

Yes, of course, though I have no rights to the original.

[kenames99]

hey atari-passion,

  could you post a photo of the cable that plugs into atari PBI and 1090XL? would be a great help to me. thanks in advance.

 

Ken

 

[atari-passion]

hello,

 

here are 2 photos of the cable.