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Justine Smithies (justine@snac.smithies.me.uk)'s status on Friday, 03-Jan-2025 08:42:00 JST Justine Smithies
In my quest to learn more about the 6309 8 bit CPU, I've discovered how to test if the CPU is indeed a real 6309 or just a 6809. #RetroComputing
LDD #$FFFF ; set all bits
CLRD ; 6309 opcode that runs as 8 bit on 6809
TSTB ; did it clear B (16 bit)?
BNE skip ; if not... not a 6309
LDMD #1 ; enable native mode
skip: