Questions tagged [mos-6522]

Questions about the MOS 6522 VIA (Versatile Interface Adapter) chip, used in e.g. the Commodore PET and the BBC Micro home computers.

7 questions
3
votes
1 answer

Does the 6522 VIA swap the registers for ports A and B compared to the 6820 PIA and 6526 CIA?

According to this preliminary datasheet and what appears to be a later CSG data sheet from some data handbook, the 6522 VIA assigns to registers 0 through 4, DR (data register) B, DR A, DDR (data direction register) B and DDR A. This is swapped…
cjs
  • 25,592
  • 2
  • 79
  • 179