I have simple Q: What a CPU - real CPU and its differences to 6502 uses DTV? Why? I was always meaning that's only emulated 6502 but why has Turbo Assembler option DTV? There must to be difference, for example in addressing... I know near nothing about DTV 'cause it's only gaming console (in my eyes).
Thank you for info.
Commodore 64 was great, Commodore 128 is bigger, better, faster and more powerful... Commodore 65 was almost here, now is back in Mega 65 and is more than ever was...
I think Mirkosoft is asking what software differences exist between 6502 and DTV-CPU. As I understand, the DTV-CPU emulates all standard (duh) and several "undocumented" 6502 opcodes... but the DTV-CPU has a few special opcodes that are not possible with 6502/6510/8502. (Sorry, I don't know what those "special" opcodes are!)
I've doing a moderate amount of research, and still don't have full answer. Anyway, here are the ones I found so far...
$12 nn = BRA pc+2+nn;branch always (relative addressing) $32 nn = SAC nn;low nibble sets .A source "hex register", high nibble sets .A destination "hex register" $42 nn = SIR nn;low nibble sets .X source and destination "hex register", high nibble sets .Y source and destination "hex register"
The "hex register" is one of 16 internal DTV-CPU registers. Normally .A maps to reg 0, .X maps to reg 1, and .Y maps to reg 2.
Also, the original DTV (version 1) does not implement undocumented 6502 opcodes. In later DTV versions, some of the undocumented 6502 opcodes have bugs.
I don't own a DTV; I found the info here. I hope that helps.
Edit Umm, I think SAC and SIR opcodes should use # for their parameter (immediate value... not a memory address). So better to write: SAC #nn SIR #nn (I hope you ML programmers know what I mean!) /Edit
Last Edit: Feb 24, 2016 2:59:53 GMT by hydrophilic: Thought of something more!