mirror of
https://github.com/fadden/6502bench.git
synced 2024-12-02 13:51:36 +00:00
3637bb964d
Split 2005x-branches-and-banks into two parts, one that stays within the 64K bounds of the 6502, one that puts code in a separate bank.
42 lines
1.1 KiB
ArmAsm
42 lines
1.1 KiB
ArmAsm
; Copyright 2018 faddenSoft. All Rights Reserved.
|
|
; See the LICENSE.txt file for distribution terms (Apache 2.0).
|
|
;
|
|
; Assembler: cc65
|
|
;
|
|
; Both cc65 (2.17) and Merlin32 (1.0) have problems computing branches that
|
|
; wrap around a bank (e.g. from $0010 to $ffd0). cc65 is slightly less
|
|
; egregious in that a workaround is possible: if you specify a label that
|
|
; is in range, and then an offset, it will generate code.
|
|
;
|
|
; 6502 version
|
|
|
|
.setcpu "6502"
|
|
|
|
.org $1000
|
|
jmp zero
|
|
|
|
.org $0000
|
|
zero: bit a:zero
|
|
low: lda zero
|
|
lda low
|
|
bne low-$40 ;reference symbol
|
|
bmi low-$40 ;EDIT: format as hex
|
|
bvs more
|
|
bvc more1
|
|
lodat: .byte $00,$01,$02 ;EDIT: set label
|
|
more: lda more-2
|
|
clc
|
|
bcc zero-$40 ;branch to high
|
|
|
|
.org $0080
|
|
more1: bit a:more1
|
|
jmp end
|
|
|
|
.org $ffc0
|
|
high:
|
|
bit high
|
|
clc
|
|
bcc high+$43 ;branch to low
|
|
|
|
end: rts
|