Chemist

Tell me please, where can I get hexademical equivalents of the Motorola 68000 assembler commands?

__________________
Thanks for attention.

Chemist.

Tony Hedstrom

I've never been able to find any on the internet. The best way to get them is to use a Sega Genesis disassembler on any Genesis game, and then read the file to find the info you need. To find a Disassembler, just do a Google search for: sega-asm.zip

Chemist

Thanks for answer.
I can't find this kind of information in the sega-asm.zip docs... I'll try to read disassemled code (with comments?) There are two (at least) hex equivalents of the m68k assembler instructions, mentiooned in your FAQ:
1. 60xx - BRAnch
2. 5338 - SUBstract

Where did you find these ones? Simply using disasm?

P.S. I've finally found The Motorola 68000 Programmers Reference manual in the i-net. Here's the part of the description of BRA instruction:

BRA

Branch always.
.
.
.
Instruction format:
0 1 1 0 0 0 0 0 [x]

[x] - 8-bit displacement.

01100000 (bin) = 60 (hex) - 60xx in your doc
It means that "60" is hex equivalent of the BRA instruction. Am I right? If you say "yes":

Here is description of SUB instruction:

SUB

Substract.
.
.
.
Instruction format:
1 0 0 1 [xx]

[xx] - 3 bites of the "Register", 3 bits of the "Opmode" and 6 bits of the "Effective Address" (I don't know about these things well)

BUT:
1001(bin) = 9(hex)
or 1001xxxx=9x(hex)

But in your manual, hex eq. of the SUB instruction is "5338". But, in any case, 9x(hex) isn't equals 53(hex). What's wrong in my results/with me?

__________________
Thanks for attention.

Chemist.

Tony Hedstrom

You won't find the info you need just by reading the stuff in the sega-asm.zip file, you need to use the program and disassemble a Genesis game, then the disassembled game file will tell you what each instruction is.

Here's an example:

00017F02: 5378 00FF7104 SUBQ.W #$1,$00FF7104

That's telling you that 5378 is a SUBQ.W instruction. The RAM address that it's subtracting from is 00FF7104.

Once you find out what the instruction is, then you can look it up in the Motorola 68000 manual to find out what it does.