git.joshuawise.com / fpgaboy.git / blame
| Commit | Line | Data |
|---|---|---|
| 91c74a3f JW |
1 | SECTION "a",HOME |
| 2 | ||
| 3 | main: | |
| 4 | ld a, $FF ; Note that we are alive. | |
| 5 | ld [$FF51],a | |
| 6 | ||
| 7 | ld sp, $DFF0 | |
| 8 | ||
| 9 | ld hl, $DF81 | |
| 10 | ld a, $80 | |
| 11 | ld [hl], a | |
| 12 | ||
| 13 | ld c, $07 | |
| 14 | ld a, $04 ;start timer, 4.096KHz | |
| 15 | ld [c], a | |
| 16 | ;diqs: ei | |
| 17 | ; ld a, $80 | |
| 18 | ; ld c, $51 | |
| 19 | ; ld [c], a | |
| 20 | ; jr diqs | |
| 21 | call irqhand | |
| 22 | ei | |
| 23 | coqs: jr coqs | |
| 24 | ||
| 25 | section "Diq", HOME[$38] | |
| 26 | fuqed: | |
| 27 | di | |
| 28 | jr fuqed | |
| 29 | ||
| 30 | section "fuq",HOME[$100] | |
| 31 | irqhand: | |
| 32 | PUSH AF | |
| 33 | PUSH BC | |
| 34 | PUSH DE | |
| 35 | PUSH HL | |
| 36 | ||
| 37 | xor a | |
| 38 | ld c, $0F ; ack the irq | |
| 39 | ld [c], a | |
| 40 | ||
| 41 | ld a, $41 ; print A | |
| 42 | call putc | |
| 43 | ||
| 44 | ld hl, $DF81 | |
| 45 | inc [hl] | |
| 46 | ld a, [hl] | |
| 47 | ld c, $51 | |
| 48 | ld [c], a | |
| 49 | ||
| 50 | ||
| 51 | POP HL | |
| 52 | POP DE | |
| 53 | POP BC | |
| 54 | POP AF | |
| 55 | RETI | |
| 56 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE | |
| 57 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE | |
| 58 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE | |
| 59 | ||
| 60 | putc: | |
| 61 | ld b, 0 | |
| 62 | ld c, $50 | |
| 63 | push af | |
| 64 | .waitport: | |
| 65 | ld a,[c] | |
| 66 | cp b | |
| 67 | jr nz,.waitport | |
| 68 | pop af | |
| 69 | ld [c],a | |
| 70 | ret |