diff options
| author | Ian C <ianc@noddybox.co.uk> | 2016-04-19 15:09:35 +0100 |
|---|---|---|
| committer | Ian C <ianc@noddybox.co.uk> | 2016-04-19 15:09:35 +0100 |
| commit | 53495c2e1b805f8192650173d3125b567a98bf0e (patch) | |
| tree | 30a7deb943ba1cff87c4f1d36d0251226ac13bef /src/example | |
| parent | 1c5087c830f290f3e88996fc1594d94abc1e3f22 (diff) | |
Fixes Gameboy output
* Fixes Gameboy output
* Documentation changes for Gameboy
* Gameboy example now works
Diffstat (limited to 'src/example')
| -rw-r--r-- | src/example/gb.asm | 86 |
1 files changed, 49 insertions, 37 deletions
diff --git a/src/example/gb.asm b/src/example/gb.asm index 10381e9..2f52e0e 100644 --- a/src/example/gb.asm +++ b/src/example/gb.asm @@ -1,22 +1,26 @@ + ; + ; This example is poor, and leaves lots of junk lymg in memory. + ; Still, it works enough to test + ; cpu gameboy option output-file,gb.gb option output-format,gameboy - ;option gameboy-irq,vbl,vbl_code + option gameboy-irq,vbl,vbl_code VRAM equ $8000 SCRN equ $9800 OAM equ $fe00 LCDC equ $ff40 STAT equ $ff41 +ISWITCH equ $ffff BGRDPAL equ $ff47 OBJ0PAL equ $ff48 OBJ1PAL equ $ff49 CURLINE equ $ff44 -READY equ $ff81 XPOS equ $ff82 VBLANK macro @@ -39,31 +43,29 @@ VBLANK macro org $150 di - xor a - ldh (READY),a ld sp,$fffe - ; Set LCD so only sprites show + ; Switch of display during setup ; VBLANK + xor a + ld (LCDC),a + + ld (XPOS),a - ld a,$81 - ldh (LCDC),a - ld a,$10 - ldh (STAT),a ld a,$e4 - ldh (BGRDPAL),a ldh (OBJ0PAL),a ldh (OBJ1PAL),a - ; Copy to VRAM + swap a + ldh (BGRDPAL),a + + ; Copy to VRAM and set up ; ld hl,VRAM ld de,sprite ld c,16 - VBLANK - .copy ld a,(de) ld (hl+),a @@ -71,12 +73,6 @@ VBLANK macro dec c jr nz,copy - ld a,1 - ldh (READY),a - - ei - - VBLANK ; Set sprite numbers ; @@ -92,9 +88,24 @@ VBLANK macro ld (OAM+7),a ld (OAM+11),a + ; Set LCD back on + ; + ld a,$83 + ldh (LCDC),a + + ; Activate VBL + ; + ld a,1 + ldh (ISWITCH),a + + ei + .idle - VBLANK + halt + nop + jr idle +vbl_code: ldh a,(XPOS) inc a ldh (XPOS),a @@ -110,23 +121,6 @@ VBLANK macro ld (OAM+8),a ld (OAM+9),a - jr idle - -vbl_code: - ldh a,(READY) - or a - jr z,finish - - ldh a,(XPOS) - inc a - ldh (XPOS),a - ld (OAM),a - ld (OAM+1),a - xor a - ld (OAM+2),a - ld (OAM+3),a - -.finish reti sprite: @@ -141,3 +135,21 @@ sprite: defb $ff,$ff defb $00,00 + ; + ; Assembly checks + ; + stop + swap a + swap b + swap c + swap d + swap e + swap h + swap l + swap (hl) + ld a,(hl+) + ld a,(hli) + ldi a,(hl) + ld a,(hl-) + ld a,(hld) + ldd a,(hl) |