Fix some sync issues? Maybe?

[fpgaboy.git] / rom.asm

diff --git a/rom.asm b/rom.asm
index 6989b2d5d53252f1b7e3345b87a1e60165801276..1504c7199bf681185a2d1d2f8422b4c3909153eb 100644 (file)
--- a/rom.asm
+++ b/rom.asm
@@ -1,25 +1,25 @@
        SECTION "a",HOME
 
 main:
-       ld c, $51       ; Note that we are alive.
-       ld a, $FF
-       ld [c],a
+       ld a, $FF       ; Note that we are alive.
+       ld [$FF51],a
        
        ld sp, $DFF0
        
-;      ld hl, $DF81
-;      ld a, $80
-;      ld [hl], a
+       ld hl, $DF81
+       ld a, $80
+       ld [hl], a
 
-;      ld c, $07
-;      ld a, $07       ;start timer, 4.096KHz
-;      ld [c], a
+       ld c, $07
+       ld a, $04       ;start timer, 4.096KHz
+       ld [c], a
 ;diqs: ei
 ;      ld a, $80
 ;      ld c, $51
 ;      ld [c], a
 ;      jr diqs
        call irqhand
+       ei
 coqs: jr coqs
 
        section "Diq", HOME[$38]
@@ -34,33 +34,20 @@ irqhand:
        PUSH DE
        PUSH HL
        
-;      ld c, $51
-;      ld a, $F0
-;      ld [c], a
-       
        xor a
        ld c, $0F       ; ack the irq
        ld [c], a
        
-       ;ld a, $41      ; print A
-       ;call putc
+       ld a, $41       ; print A
+       call putc
        
-;      ld hl, $DF81
-;      ld a, [hl]
-;      ld b, 1
-;      add b
-       ld a, $08
-       ld hl, $FF51
-;      ld c, $51
-       nop
-       nop
-       ld [hl], a
+       ld hl, $DF81
+       inc [hl]
+       ld a, [hl]
+       ld c, $51
+       ld [c], a
 
 
-;      ld c, $51
-;      ld a, $0F
-;      ld [c], a
-       
        POP HL
        POP DE
        POP BC
@@ -69,3 +56,15 @@ irqhand:
        db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
        db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
        db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE
+
+putc:
+       ld b, 0
+       ld c, $50
+       push af
+.waitport:
+       ld a,[c]
+       cp b
+       jr nz,.waitport
+       pop af
+       ld [c],a
+       ret