ack/mach/z80/libem/sts.s

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540 B
ArmAsm
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1985-03-29 21:44:50 +00:00
.define .sts
! use trp.z
! object size given by 2-byte integer on
! top of stack.
! parameters:
! on stack
! checks if #bytes is even or 1,
! else traps
.sts:
pop ix ! save return address
pop de ! # bytes to transfer
pop hl ! destination address
srl d ! divide de by 2
rr e
jr nc,1f ! see if it was odd
ld a,e ! yes, must be 1
or d
jr nz,.trp.z ! no, error
pop de ! transfer 1 byte,
! padded with zeroes
ld (hl),e
jp (ix)
1:
pop bc
ld (hl), c
inc hl
ld (hl),b
inc hl
dec de
ld a,e
or d
jr nz,1b
jp (ix)