acme/ACME_Lib/cbm/c64/memcopy.a
2016-06-06 09:25:33 +00:00

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;ACME 0.95.7
!ifdef lib_cbm_c64_memcopy_a !eof
lib_cbm_c64_memcopy_a = 1
; this macro inserts code to copy a memory block.
; it calls a function from the basic interpreter, so:
; - BASIC ROM must be banked in
; - the source block must be readable (so no RAM hidden under BASIC, Kernal, or I/O)
; - the target block must be writable (so no RAM hidden under I/O)
; higher addresses are copied first, so:
; - moving data to higher addresses works even if areas overlap
; - moving data to lower addresses only works if areas do not overlap
!macro basic_memcopy .src_start, .src_end, .target_start {
!address {
.z_target_end = $58
.z_src_end = $5a
.z_src_start = $5f
.fn = $a3bf
}
lda #<.src_start
ldx #>.src_start
sta .z_src_start
stx .z_src_start + 1
lda #<.src_end
ldx #>.src_end
sta .z_src_end
stx .z_src_end + 1
lda #<(.target_start + .src_end - .src_start)
ldx #>(.target_start + .src_end - .src_start)
sta .z_target_end
stx .z_target_end + 1
jsr .fn
}