3 ms·
I used multiple NOP all the time when learning to code 6502 on the VIC-20. With no assembler and typing in hex valued opcodes by hand, it was useful to leave g
by WhitneyLand 10y ago
I used multiple NOP all the time when learning to code 6502 on the VIC-20. With no assembler and typing in hex valued opcodes by hand, it was useful to leave gaps during during development to avoid retyping everything too often.
6502 actually had pretty good performance at the time on a per cycle basis.
- drbw 10y agoI'm somewhat surprised that I can remember that the NOP opcode was EA. Amazing what sticks in your mind for almost forty years...
- phkahler 10y ago>> I'm somewhat surprised that I can remember that the NOP opcode was EA. Amazing what sticks in your mind for almost forty years... poke 19215,25 It was used on MS basic on the Interact computer (1978/9) to enable peek and poke. Oddly the poke instruction would execute and THEN error, but poking this one value disabled the error. There was also a set of 3 pokes that disabled address checking which was used to prevent people from reading the system ROM and the basic interpreter itself. I believe I still have quite a collection of the "Interaction" newsletter that was published in the Detroit area about this machine, which is where the above info came from. Yeah, the stuff we remember...