ack/mach/z80/libmon/putchr.nas.s

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ArmAsm
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1985-04-01 14:44:26 +00:00
.define putchr
! output routine in monitor
CRT = 0x013B
! output a charcter
! entry: ascii character in a
putchr:
push hl
push bc
ld hl,tab
ld b,5
1: cp (hl)
jr z,fetch
inc hl
inc hl
djnz 1b
2: call CRT
pop bc
pop hl
ret
fetch: inc hl
ld a,(hl)
jr 2b
! conversion table for nascom characters
tab: .byte 0x0D,0x00
.byte 0x1B,0x1E
.byte 0x08,0x1D
.byte 0x0A,0x1F
.byte 0x7F,0x00