rom4x/rom5x/B1_C53D_patch_out_rom_cksum.s

14 lines
429 B
ArmAsm
Raw Normal View History

2017-03-11 08:19:40 +00:00
; Patch the Apple IIc+ diagnostics to skip the ROM checksum test.
; We should really examine the routine at $D249 in the aux firmware
; to see if we can calculate a new checksum.
; the $D249 routine copies a small routine into the zero page that
; calculates the checksum. It returns with carry set = error and
; carry clear = OK. So we just patch the JSR to always clear the
; carry. For now.
* = $C53D
.text
nop
nop
clc