6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2025-08-08 06:25:17 +00:00
Code Issues Projects Releases Wiki Activity

Used I/O mirror locations that avoid (redirected) zero-page accesses.

Browse Source
This commit is contained in:
Greg King
2015-09-29 12:39:58 -04:00
committed by Oliver Schmidt
parent c39d07dd17
commit 203200e259
6 changed files with 17 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
asminc/pce.inc
View File

@@ -34,11 +34,13 @@ VDC_LENR = 18 ; (DMA) Length Register
VDC_SATB = 19 ; Sprite Attribute Table VDC_SATB = 19 ; Sprite Attribute Table
; VDC port ; VDC port
; Note: absolute addressing mode must be used when writing to this port ; Note: The zero-page addressing mode is redirected to page $20.
; Therefore, absolute addressing mode must be used when writing to this port.
; We force it by using mirror locations that are outside of zero page.
VDC_CTRL = $0000 VDC_CTRL := $0200
VDC_DATA_LO = $0002 VDC_DATA_LO := $0202
VDC_DATA_HI = $0003 VDC_DATA_HI := $0203
; huc6260 - Video Color Encoder (vce) ; huc6260 - Video Color Encoder (vce)

4
libsrc/pce/clrscr.s
View File

@@ -16,9 +16,9 @@ rowloop:
ldx #$80 ldx #$80
colloop: colloop:
lda #' ' lda #' '
sta a:VDC_DATA_LO sta VDC_DATA_LO
lda #$02 lda #$02
sta a:VDC_DATA_HI sta VDC_DATA_HI
dex dex
bne colloop bne colloop

4
libsrc/pce/conio.s
View File

@@ -90,8 +90,8 @@ charloop:
lineloop: lineloop:
lda (ptr1) lda (ptr1)
eor tmp1 eor tmp1
sta a:VDC_DATA_LO ; bitplane 0 sta VDC_DATA_LO ; bitplane 0
stz a:VDC_DATA_HI ; bitplane 1 stz VDC_DATA_HI ; bitplane 1
clc ; increment font pointer clc ; increment font pointer
lda ptr1 lda ptr1

8
libsrc/pce/cputc.s
View File

@@ -69,15 +69,15 @@ putchar:
st0 #VDC_MAWR ; Memory Adress Write st0 #VDC_MAWR ; Memory Adress Write
lda SCREEN_PTR lda SCREEN_PTR
sta a:VDC_DATA_LO sta VDC_DATA_LO
lda SCREEN_PTR + 1 lda SCREEN_PTR + 1
sta a:VDC_DATA_HI sta VDC_DATA_HI
st0 #VDC_VWR ; VWR st0 #VDC_VWR ; VWR
txa txa
sta a:VDC_DATA_LO ; character sta VDC_DATA_LO ; character
lda CHARCOLOR lda CHARCOLOR
@@ -87,7 +87,7 @@ putchar:
asl a asl a
ora #$02 ora #$02
sta a:VDC_DATA_HI sta VDC_DATA_HI
rts rts

2
libsrc/pce/irq.s
View File

@@ -32,7 +32,7 @@ IRQStub:
; Save the display-source flags (and, release the interrupt). ; Save the display-source flags (and, release the interrupt).
; ;
ldy a:VDC_CTRL ldy VDC_CTRL
sty vdc_flags sty vdc_flags
ldy #<(__INTERRUPTOR_COUNT__ * 2) ldy #<(__INTERRUPTOR_COUNT__ * 2)

4
libsrc/pce/vdc.s
View File

@@ -7,7 +7,7 @@ HIRES = 1
.export vdc_init .export vdc_init
vdc_init: vdc_init:
lda a:VDC_CTRL lda VDC_CTRL
VREG $00, $0000 ; MAWR VREG $00, $0000 ; MAWR
VREG $01, $0000 ; MARR VREG $01, $0000 ; MARR
@@ -37,5 +37,5 @@ vdc_init:
.endif .endif
lda a:VDC_CTRL lda VDC_CTRL
rts rts