git.joshuawise.com / fpgaboy.git / blame
| Commit | Line | Data |
|---|---|---|
| 616eebe0 | 1 | SECTION "a",HOME |
| 20204e79 | 2 | |
| 616eebe0 | 3 | main: |
| 00573fd5 JW |
4 | ld a, $FF ; Note that we are alive. |
| 5 | ld [$FF51],a | |
| 62940da0 | 6 | |
| 9c834ff2 JW |
7 | ld sp, $DFF0 |
| 8 | ||
| 30ef1ae0 JW |
9 | ld hl, $DF81 |
| 10 | ld a, $80 | |
| 11 | ld [hl], a | |
| 9c834ff2 | 12 | |
| 30ef1ae0 JW |
13 | ld c, $07 |
| 14 | ld a, $04 ;start timer, 4.096KHz | |
| 15 | ld [c], a | |
| 5bac4cf0 JW |
16 | ;diqs: ei |
| 17 | ; ld a, $80 | |
| 18 | ; ld c, $51 | |
| 19 | ; ld [c], a | |
| 20 | ; jr diqs | |
| 21 | call irqhand | |
| 30ef1ae0 | 22 | ei |
| 5bac4cf0 | 23 | coqs: jr coqs |
| 20204e79 | 24 | |
| 5bac4cf0 JW |
25 | section "Diq", HOME[$38] |
| 26 | fuqed: | |
| 31833112 | 27 | di |
| 5bac4cf0 | 28 | jr fuqed |
| 20204e79 | 29 | |
| 5bac4cf0 | 30 | section "fuq",HOME[$100] |
| 31833112 JW |
31 | irqhand: |
| 32 | PUSH AF | |
| 33 | PUSH BC | |
| 34 | PUSH DE | |
| 35 | PUSH HL | |
| 9c834ff2 | 36 | |
| 31833112 JW |
37 | xor a |
| 38 | ld c, $0F ; ack the irq | |
| 39 | ld [c], a | |
| 9c834ff2 | 40 | |
| 30ef1ae0 JW |
41 | ld a, $41 ; print A |
| 42 | call putc | |
| 9c834ff2 | 43 | |
| 30ef1ae0 | 44 | ld hl, $DF81 |
| f9000d73 | 45 | inc [hl] |
| 30ef1ae0 | 46 | ld a, [hl] |
| 30ef1ae0 JW |
47 | ld c, $51 |
| 48 | ld [c], a | |
| 9c834ff2 JW |
49 | |
| 50 | ||
| 31833112 JW |
51 | POP HL |
| 52 | POP DE | |
| 53 | POP BC | |
| 54 | POP AF | |
| 55 | RETI | |
| 5bac4cf0 JW |
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 | |
| 30ef1ae0 JW |
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 |