Re: Cloning BOOT13, Pt.2

[Linards Ticmanis <ticmanis@gmx.de>]

Linards Ticmanis wrote:

> Here's the 13-sector boot code from CP/M's BOOT.COM. The only changes 
> from the ROM are in the marked lines if I looked right. This code wants 
> to live at $6000. You might see what you can do with it.

I should add, the code in BOOT13.COM ends with a jump to address $1153; 
here's what's to be found there:

0153 A9 A9     LDA #$A9
0155 8D 1F 03  STA $031F
0158 A9 60     LDA #$60
015A 8D 20 03  STA $0320
015D 4C 01 03  JMP $0301

Obviously the code that gets loaded to 0301 still needs access to the 
boot ROM code to do its job, and when it can't find it where it is 
expected, the second stage of booting won't work.

--
Linards Ticmanis