Commodore 1570 - Page 105

; subroutines (refer to Cl28 User's Guide for SPINP and SPOUT vectors)
spout Ida mmureg
; change serial direction
to output
ora
#$08
sta mmureg
Ida
#$7f
sta dlicr
; no irq's
Ida
#$00
sta dltirnh
Ida
#$03
sta dltirnl
; low 6
us bit (fastest)
Ida dIcra
and
#$80
; keep TOD
ora
#$55
sta dIcra
; setup CRA for output
bit
dlicr
; elr pending
rts
spinp Ida
dlcra
; input, 6526
and
#$80
ora
#$08
sta
dicra
Ida
mmureg
and
#$f7
sta
mmureg
; mmu serial direction in
rts
elklo Ida
d2pra
; set clock low
ora #clkout
sta d2pra
rts
clkhi Ida
d2pra
; set clock high
and
#$ff-clkout
sta
d2pra
rts
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