X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/f6fa1d6e1393de5d18302b8674ed1616afdfcefb..14778cde2df07491e9c2e8da0e8a1ab8724e6cec:/diag.asm diff --git a/diag.asm b/diag.asm index 8e09874..e7bb0d4 100644 --- a/diag.asm +++ b/diag.asm @@ -32,6 +32,8 @@ main: ld hl, signon call puts + + call putscreen ei @@ -48,6 +50,91 @@ main: signon: db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0 +tiles: + db %01111100 + db %11000110 + db %11000110 + db %11111110 + db %11000110 + db %11000110 + db %11000110 + db %00000000 + + db %11111100 + db %11000110 + db %11000110 + db %11111100 + db %11000110 + db %11000110 + db %11111100 + db %00000000 + + db %01111100 + db %11000110 + db %11000010 + db %11000000 + db %11000010 + db %11000110 + db %01111100 + db %00000000 + + db %11111100 + db %11000110 + db %11000110 + db %11000110 + db %11000110 + db %11000110 + db %11111100 + db %00000000 + +putscreen: + ; Wait for vblank + call .vblwait + + ld hl, $8000 ; Copy two tiles. + ld de, tiles + ld c, $20 +.cloop: push hl + ld h, d + ld l, e + ld a, [hl] + inc de + pop hl + ld [hli], a + ld [hli], a + dec c + xor a + cp c + jr nz, .cloop + + ld hl, $9800 +.vloop: call .vblwait + ld c, $40 + ld b, 0 +.loop: ld a, b + inc b + and $03 + ld [hli], a + ld a, h + cp $9C + ret z + dec c + xor a + cp c + jr nz,.loop + jr .vloop + +.vblwait: +.stat1: ld a, [$FF41] ; STAT + and $03 + cp $00 + jp nz, .stat1 +.stat2: ld a, [$FF41] + and $03 + cp $01 + jr nz, .stat2 + ret + vbl: PUSH AF PUSH BC @@ -57,11 +144,34 @@ vbl: xor a ld [$FF0F], a - ld c, $42 ; SCY - ld a, [c] - inc a - ld [c], a + ld a, [$FF51] + ld b, a + and $80 + cp $80 + jr nz, .nothing + ld c, $0 + + ld a, b + and $1 + cp c + call nz, .scyup + + ld a, b + and $2 + cp c + call nz, .scydown + + ld a, b + and $4 + cp c + call nz, .scxup + + ld a, b + and $8 + cp c + call nz, .scxdown +.nothing: POP HL POP DE POP BC @@ -69,6 +179,23 @@ vbl: RETI +.scyup: ld hl, $FF42 + inc [hl] + ret + +.scydown: ld hl, $FF42 + dec [hl] + ret + +.scxup: ld hl, $FF43 + inc [hl] + ret + +.scxdown: ld hl, $FF43 + dec [hl] + ret + + lcdc: PUSH AF PUSH BC