Created
March 15, 2016 11:05
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FAP's first hello world program
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| org 0x0 | |
| xor d | |
| xor e | |
| xor b | |
| ld sp, 0x7fff | |
| ld hl, 0x92bf ; fill attribute RAM with 0x3c, yellow | |
| ld de, 2400 | |
| ld b, 0x3c | |
| clear_attri: | |
| call check | |
| ld (hl), b | |
| dec hl | |
| dec de | |
| ld a,d | |
| or e | |
| jp nz,clear_attri | |
| ld hl, 0x895f ; fill char RAM with 0, effectively clearing screen | |
| ld de, 2400 | |
| ld b, 0 | |
| clear_char: | |
| call check | |
| ld (hl), b | |
| dec hl | |
| dec de | |
| ld a,d | |
| or e | |
| jp nz,clear_char | |
| ld hl, 0x8001 ; then print "hello world" | |
| call check | |
| ld (hl), 'h' | |
| ld hl, 0x8002 | |
| call check | |
| ld (hl), 'e' | |
| ld hl, 0x8003 | |
| call check | |
| ld (hl), 'l' | |
| ld hl, 0x8004 | |
| call check | |
| ld (hl), 'l' | |
| ld hl, 0x8005 | |
| call check | |
| ld (hl), 'o' | |
| ld hl, 0x8007 | |
| call check | |
| ld (hl), 'w' | |
| ld hl, 0x8008 | |
| call check | |
| ld (hl), 'o' | |
| ld hl, 0x8009 | |
| call check | |
| ld (hl), 'r' | |
| ld hl, 0x800a | |
| call check | |
| ld (hl), 'l' | |
| ld hl, 0x800b | |
| call check | |
| ld (hl), 'd' | |
| end: jp end | |
| ; check if GPU copy is underway, wait if it does | |
| check: ld a, (0x92c0) | |
| or a | |
| jp nz,check | |
| ret |
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