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3.0 KiB
3.0 KiB
Emitting Ophis from SixtyPical Programs
-> Tests for functionality "Emit ASM for SixtyPical program"
-> Functionality "Emit ASM for SixtyPical program" is implemented by
-> shell command "bin/sixtypical emit %(test-file)"
Emitting an if
.
| assign byte screen $0400
| routine main {
| lda screen
| cmp screen
| if beq {
| tax
| } else {
| tay
| }
| sta screen
| }
= jmp main
= main:
= lda screen
= cmp screen
= BEQ _label_1
= tay
= jmp _past_1
= _label_1:
= tax
= _past_1:
= sta screen
= rts
=
= .alias screen 1024
Emitting a repeat
.
| assign byte screen 1024
| reserve byte zero
| routine main {
| ldy zero
| repeat bne {
| inc screen
| dey
| cpy zero
| }
| sty screen
| }
= jmp main
= main:
= ldy zero
=
= _repeat_1:
= inc screen
= dey
= cpy zero
= BNE _repeat_1
= sty screen
= rts
=
= .alias screen 1024
= zero: .byte 0
Nested ifs.
| routine main {
| if beq {
| if bcc {
| lda #0
| } else {
| if bvs {
| lda #1
| } else {
| lda #2
| }
| }
| } else {
| lda #3
| }
| }
= jmp main
= main:
= BEQ _label_3
= lda #3
= jmp _past_3
= _label_3:
= BCC _label_2
= BVS _label_1
= lda #2
= jmp _past_1
= _label_1:
= lda #1
= _past_1:
= jmp _past_2
= _label_2:
= lda #0
= _past_2:
= _past_3:
= rts
Installing an interrupt handler (at the Kernal level, i.e. with CINV)
| assign byte screen 1024
| assign vector cinv 788
| reserve vector save_cinv
|
| routine main {
| sei {
| copy cinv save_cinv
| copy routine our_cinv to cinv
| }
| }
|
| routine our_cinv {
| inc screen
| jmp (save_cinv)
| }
= jmp main
= main:
= sei
= lda cinv
= sta save_cinv
= lda cinv+1
= sta save_cinv+1
= lda #<our_cinv
= sta cinv
= lda #>our_cinv
= sta cinv+1
= cli
= rts
=
= our_cinv:
= inc screen
= jmp (save_cinv)
= rts
=
= .alias screen 1024
= .alias cinv 788
= save_cinv: .word 0
Copy command: immediate -> byte
| reserve byte position
| routine main {
| copy #23 position
| }
= jmp main
= main:
= lda #23
= sta position
= rts
=
= position: .byte 0
Copy command: immediate -> word
| reserve word position
| routine main {
| copy #$0400 position
| }
= jmp main
= main:
= lda #0
= sta position
= lda #4
= sta position+1
= rts
=
= position: .word 0