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Post by mirkosoft on Feb 19, 2016 21:50:54 GMT
Hi!
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.
Miro
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Post by gsteemso on Feb 20, 2016 0:52:27 GMT
Apologies, but I’m finding your phrasing to be a bit harder to decode than usual. Are you asking what specific chip the 64DTV uses as a CPU?
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Post by robertb on Feb 20, 2016 4:08:03 GMT
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Post by hydrophilic on Feb 21, 2016 8:42:38 GMT
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!)
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Post by mirkosoft on Feb 21, 2016 9:33:12 GMT
Yes Robert, I want to know programming difference - opcodes.
I found them not anywhere.
Miro
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Post by robertb on Feb 22, 2016 2:07:34 GMT
Yes Robert, I want to know programming difference - opcodes. I found them not anywhere. Ah, a question for Jeri Ellsworth. If I see her at Maker Faire this year in May, Robert Bernardo Fresno Commodore User Group www.dickestel.com/fcug.htm |
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Post by hydrophilic on Feb 24, 2016 0:45:29 GMT
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. EditUmm, 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 |
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Post by mirkosoft on Feb 24, 2016 2:54:01 GMT
Thank you!
I will search if will find any time
Miro
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