67 lines
828 B
ArmAsm
67 lines
828 B
ArmAsm
.define EQU =
|
|
|
|
PTR EQU $06
|
|
PTRH EQU $07
|
|
|
|
WRAPL EQU $08
|
|
WRAPH EQU $09
|
|
|
|
SIZEL EQU $0A
|
|
SIZEH EQU $0B
|
|
|
|
tx_copy:
|
|
|
|
lda #0 ; always copying from 0x4000
|
|
sta PTR
|
|
lda #$40
|
|
sta PTR+1
|
|
|
|
ldx #SIZEH ; number of 256-byte blocks
|
|
beq copy_remainder ; if none, skip ahead
|
|
|
|
ldy #0
|
|
copy256:
|
|
lda (PTR),y
|
|
sta $C0B7 ; change based on uthernet slot
|
|
|
|
cmp WRAPH,x
|
|
bne nowrap256
|
|
|
|
cmp WRAPL,y
|
|
bne nowrap256
|
|
|
|
lda #$40
|
|
sta $C0B5
|
|
lda #$00
|
|
sta $C0B6 ; wrap tx buffer address to 0x4000
|
|
|
|
nowrap256:
|
|
iny
|
|
bne copy256
|
|
|
|
inc PTR+1 ; update 16-bit pointer
|
|
dex ; finish a 256 byte block
|
|
bne copy256
|
|
|
|
ldx #SIZEL
|
|
copy_remainder:
|
|
lda (PTR),y
|
|
sta $C0B7 ; change based on uthernet slot
|
|
|
|
cmp WRAPL,y
|
|
bne nowrap_r
|
|
|
|
lda #$40
|
|
sta $C0B5
|
|
lda #$00
|
|
sta $C0B6 ; wrap tx buffer address to 0x4000
|
|
|
|
nowrap_r:
|
|
iny
|
|
dex
|
|
bne copy_remainder
|
|
|
|
rts
|
|
|
|
|