Unknown 8085 opcodes

Tony Duell ard.p850ug1 at gmail.com
Wed Jan 11 12:08:28 CST 2017

On Wed, Jan 11, 2017 at 6:01 PM, Fred Cisin <cisin at xenosoft.com> wrote:
> Quite realistic would be for a disassembler that couldn't recognize an
> opcode to display it as
> DB 1A ; Esc
> DB 65 ; 'e'
> DB 09

I once used a disassembler (I can't remember for what CPU) that would
put a comment on each line giving the ascii character equivalents of the

So you would get something like (totally ficticious instruction set) :

0100 48 65 6C  ST R8 (656C)  ; Hel

You (the user) could then decide if the instruction or text made more
sense. Of course it didn't help with, say floating point numbers, or RAD50
strings or...

> Code immediately following an unconditional JMP is likely to be data, but
> could just as easily be the destination of some other JMP, so a disassemble
> can't make assumptions.
> A disassembler does not convert bytes into code.  It merely assists YOU in
> doing that.

Yes, like all tools, you have to think when you are using it.


More information about the cctalk mailing list