Expanding Atari 800 To 64K

I have an Atari 800 which I recently expanded to 48K by adding an Intec 32K board. This addition leaves an open slot in my memory compartment. Can I now just add a 16K board in this open slot to bring my machine up to 64K? Or do I need some additional hardware or software to make this upgrade possible?

Neil G. Wyatt II

It's not that easy. The 6502 in your computer can access 64K at a time, but that includes both ROM and RAM. Your machine needs 16K of space for ROM and other system memory, leaving you with a maximum of 48K. Adding another 16K would only hopelessly confuse your machine. There are companies which manufacture 64K RAM boards. Some of these let you rotate segments of your memory with a large bank of extra memory. Others let you temporarily make the ROMs disappear, revealing underlying RAM. This is the technique used in the new Atari XL computers, and on the Commodore 64. At least one company lets you plug your existing RAM chips into a bare board to save you money in the upgrade.