git.joshuawise.com / fpgaboy.git / blame
| Commit | Line | Data |
|---|---|---|
| 616eebe0 | 1 | SECTION "a",HOME |
| 20204e79 | 2 | |
| 616eebe0 | 3 | main: |
| 20204e79 | 4 | ld c, $51 ; Note that we are alive. |
| 616eebe0 JW |
5 | ld a, $FF |
| 6 | ld [c],a | |
| 62940da0 | 7 | |
| 9c834ff2 JW |
8 | ld sp, $DFF0 |
| 9 | ||
| 30ef1ae0 JW |
10 | ld hl, $DF81 |
| 11 | ld a, $80 | |
| 12 | ld [hl], a | |
| 9c834ff2 | 13 | |
| 30ef1ae0 JW |
14 | ld c, $07 |
| 15 | ld a, $04 ;start timer, 4.096KHz | |
| 16 | ld [c], a | |
| 5bac4cf0 JW |
17 | ;diqs: ei |
| 18 | ; ld a, $80 | |
| 19 | ; ld c, $51 | |
| 20 | ; ld [c], a | |
| 21 | ; jr diqs | |
| 22 | call irqhand | |
| 30ef1ae0 | 23 | ei |
| 5bac4cf0 | 24 | coqs: jr coqs |
| 20204e79 | 25 | |
| 5bac4cf0 JW |
26 | section "Diq", HOME[$38] |
| 27 | fuqed: | |
| 31833112 | 28 | di |
| 5bac4cf0 | 29 | jr fuqed |
| 20204e79 | 30 | |
| 5bac4cf0 | 31 | section "fuq",HOME[$100] |
| 31833112 JW |
32 | irqhand: |
| 33 | PUSH AF | |
| 34 | PUSH BC | |
| 35 | PUSH DE | |
| 36 | PUSH HL | |
| 9c834ff2 | 37 | |
| 31833112 JW |
38 | xor a |
| 39 | ld c, $0F ; ack the irq | |
| 40 | ld [c], a | |
| 9c834ff2 | 41 | |
| 30ef1ae0 JW |
42 | ld a, $41 ; print A |
| 43 | call putc | |
| 9c834ff2 | 44 | |
| 30ef1ae0 JW |
45 | ld hl, $DF81 |
| 46 | ld a, [hl] | |
| 47 | ld b, 1 | |
| 48 | add b | |
| 49 | ld c, $51 | |
| 50 | ld [c], a | |
| 5bac4cf0 | 51 | ld [hl], a |
| 9c834ff2 JW |
52 | |
| 53 | ||
| 31833112 JW |
54 | POP HL |
| 55 | POP DE | |
| 56 | POP BC | |
| 57 | POP AF | |
| 58 | RETI | |
| 5bac4cf0 JW |
59 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE |
| 60 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE | |
| 61 | db $18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE,$18,$FE | |
| 30ef1ae0 JW |
62 | |
| 63 | putc: | |
| 64 | ld b, 0 | |
| 65 | ld c, $50 | |
| 66 | push af | |
| 67 | .waitport: | |
| 68 | ld a,[c] | |
| 69 | cp b | |
| 70 | jr nz,.waitport | |
| 71 | pop af | |
| 72 | ld [c],a | |
| 73 | ret |