2014-02-02 01:26:39 +00:00
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AskSerial:: ; 2063
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2013-09-09 03:53:04 +00:00
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; send out a handshake while serial int is off
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2015-02-10 23:14:41 +00:00
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ld a, [wc2d4]
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2013-09-09 03:53:04 +00:00
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bit 0, a
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ret z
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2015-02-10 23:14:41 +00:00
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ld a, [wc2d5]
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2013-09-09 03:53:04 +00:00
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and a
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ret nz
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; once every 6 frames
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2015-02-10 23:14:41 +00:00
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ld hl, wca8a
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2013-09-09 03:53:04 +00:00
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inc [hl]
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ld a, [hl]
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cp 6
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ret c
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xor a
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ld [hl], a
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ld a, $c
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2015-02-10 23:14:41 +00:00
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ld [wc2d5], a
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2013-09-09 03:53:04 +00:00
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; handshake
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ld a, $88
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ld [rSB], a
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; switch to internal clock
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ld a, %00000001
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ld [rSC], a
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; start transfer
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ld a, %10000001
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ld [rSC], a
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ret
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; 208a
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