rom4x/rom5x/B0_CFF9_switch_cmd.s

16 lines
522 B
ArmAsm
Raw Normal View History

2017-03-11 08:19:40 +00:00
; This is the dispatch routine to call the primary ROM 5X
; functions of intercepting RESET and the boot process.
; If one enters at $CFF9, the command $A9 is loaded and
; we go to the BELL1 hijack. If entering at $CFFA, we
; load the command $EA and proceed the same way.
; thus we get two dispatch codes in 6 bytes.
2017-03-19 03:00:43 +00:00
.include "iic+.defs"
.code
.org $cff9 ; 7 bytes available here, but don't count on $CFFF
2017-02-12 19:53:47 +00:00
lda #$a9 ; lda opcode
nop ; jmp/jsr $cffa does lda #$ea
2017-12-11 02:01:37 +00:00
jmp $c7fc ; jump to 5X dispatcher
2017-02-12 19:53:47 +00:00
; total 6 bytes.