Quote Originally Posted by tictac
If u dont want to use WPCREDIT u can built isa rom and embended it into biosfilewith cbrom... build a rom with:
Code:
header: 55 AA  ; Boot Able rom
jmp init ; jump to code intialization
retf ; return far to system bios file

INIT
pushad  
push eax
push edx
mov eax,0x80002184; eax=Bus0Dev2Func1,Offset 84,85,86,87
mov dx,0cf8 ; set dx as adress port
out dx,eax ; send the address to IO Space throgh dx port
mov dx,0cfc ; set dx as data port
in eax,dx ;Receive the data into eax for the address we sent through dx port
and eax,XXXXXX ; Change the data
or eax,XXXXXX ; Change the data
out eax,dx ; Send back the modded data through dx port
pop edx,
pop eax
popad
ret ; return to header

last bit; use 8 bit checksum
then install it with cbrom
cbrombiosname.bun /isa filename.bin

cheers
tictac,

would you be so kind and tell something more about this? i would like to build my custom isa option rom and include it into the bios image, but i have a few questions. Which utility to program in do you use to build these option roms? I need to change the Bypass Max, located at offset 0x93h, bit 1-3 to 111 (or 7x) and the max async latency located at offset 0x94h bit 0-3 set to 1000 (8ns). I need that to include into BIOS cause else i can't run 7-3-3-2.5 timings on TCCD. If I use A64tweaker and set that at startup together with reconfiguration of timings from 8-4-4-3 to 7-3-3-2.5, it freezes. It doesn't freeze if i first set those two parameters and then edit the timings, but i must do that every time windows boots up, so I guess it would be a solution, to set those two in the isa option rom (i could set agressive timings in BIOS then too i think).

please answer tictac, i was searching the net for how to program isa option rom but i didn't find anything.