prodos-path/echo.cmd.s

51 lines
915 B
ArmAsm

.include "apple2.inc"
.include "more_apple2.inc"
.org $4000
jsr CROUT
ldx #0
;; Skip any leading spaces
jsr skip_spaces
;; Invoked with "-" ?
lda INBUF,x
cmp #'-'|$80
bne :+
inx
:
;; Skip any more leading spaces
jsr skip_spaces
;; Skip command name (i.e. "echo")
txa
clc
adc #cmd_length
tax
;; Skip leading spaces before string to echo
jsr skip_spaces
;; Echo string
: lda INBUF,x
jsr COUT
cmp #$D | $80
beq exit
inx
jmp :-
exit: clc
rts
.proc skip_spaces
lda INBUF,x
cmp #' '|$80
beq :+
rts
: inx
jmp skip_spaces
.endproc
cmd_length = .strlen("echo")