ref: 3ac5d20c753aab09a5aeabcd1677ff4812d4a10c
dir: /home/handshake.asm/
AskSerial: ; 2063 ; send out a handshake while serial int is off ld a, [$c2d4] bit 0, a ret z ld a, [$c2d5] and a ret nz ; once every 6 frames ld hl, $ca8a inc [hl] ld a, [hl] cp 6 ret c xor a ld [hl], a ld a, $c ld [$c2d5], a ; handshake ld a, $88 ld [rSB], a ; switch to internal clock ld a, %00000001 ld [rSC], a ; start transfer ld a, %10000001 ld [rSC], a ret ; 208a