RTIVec = 00ec

PutC = bfd3

org c200

lds #dfff

ldaa #7e

staa 00eb

ldd #RTISvc

std RTIVec

ldx #1000

bset 26,x,03

ldaa #30

staa c000

bset 24,x,40

cli

Wait: bra Wait

RTISvc: ldx #1000

bset 25,x,40

ldaa c000

cmpa #3a

beq RTIB

RTIA: psha

cli

jsr PutC

sei

inc c000

rti

RTIB: ldaa #0a

psha

cli

jsr PutC

sei

ldaa #0d

psha

cli

jsr PutC

sei

ldaa #30

staa c000

bra RTIA