grossman@bbn.com (Martin Grossman) (06/17/88)
IBM XT clone (SYNCO PC-1600) (ERSO BIOS 3.22) 1) I have tried for 2 months to get the PD bios to work on my system. Finaly I got it to work in the following combo. ERSO bios in standard spot f000:e000 PD bios in vacant spot f000:4000 (ie last ROM spot checked for) I modified the PD bios so it has signature bytes at front and when it got control totaly took over....this worked fine BUT not all my ram was being checked twice (ie 3 minutes to cold boot) 2) when I recompiled PD Bios to run at f000:e000 everything works but the KB is locked up (ie cant get any input to system) 3) finaly after disassembly of ERSO I found out how it enables the kb.... following is the code that I put into a .COM file to get KB working then I added it to the PD bios and all works fine now. SOMEONE PLEASE EMAIL ME WHAT THIS IS DOING. CALL DOIT INT 20 DOIT: IN AL,21 MOV BH,AL IN AL,61 MOV BL,AL MOV AL,FF OUT 21,AL IN AL,61 AND AL,7F OUT 61,AL MOV CX,0006 MOV SI,TABLE LOOP: MOV AL,CS:[SI] OUT 68,AL INC SI LOOP LOOP IN AL,60 IN AL,60 MOV AL,BL OUT 61,AL MOV AL,BH OUT 21,AL RET TABLE DB 00h,00h,00h,40h,0DEh,037h ; this doesnt look like AT codes. email to grossman@cc5.bbn.com