[Diy_efi] finding maps

Brian Sidebotham BRIAN at lightprocessor.co.uk
Thu Jun 13 13:30:19 GMT 2002


On this subject, I don't seem to be able to find out about folded 
code. Is it just copy the first 1k of data to the end of the file? I have 
a 32k EPROM which I know is folded code, but I don't know how to 
unfold it.

I think your method below will help me immensly with decoding my 
EPROM too. Thanks for that...

Regards, Brian Sidebotham.

> >Given an EPROM, what is the best method of finding the various maps
> >hidden therein?<
> 
> Do a disassembly and then shove that into excel.  Sort by pneumonic
> and pick all ldx ldaa ldab and ldy values.  Sort these by called value
> (#$xxxx, Lxxxx, etc...)  Convert the xxxx to decimal and subtract to
> find number of bytes between callouts.  Pick the largest ones and find
> them in the disassembly.  Look at the routine called for
> interpolating.  The largest tables should give you the 3-d routine and
> the 3-d routine will give you the location of all 3-d tables.  Repeat
> for 2-d interpolation. Use abx to find indexed tables.  Most tables
> should be near each other.
> 
> HTH
> 
> JG


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi



More information about the Diy_efi mailing list