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INPUT/OUTPUT PROVISIONS
26.2 -- Device Independent I/O
..
*DEVICE DRIVER ENTRY
POINTS
*
HRDRV$ EGU
CLC
*
TURN DEVICE ON
BRA
RETURN
..
*
CLC
BRA
JSR
TURN
DEVICE
OFF
RETURN
INITR
DEVICE
INITIALIZATION
CLC
DEVICE TERMINATION
BRA
RETURN
*
BSR
TAB
BCe
TSX
LDX
LDX
LDX
LDAA
STAA
RETURN
TSX
LDX
INS
INS
JMP
*
GETC?
RETURN
O,X
O,X
Q,X
#I$EOM
IOCSTA,X
x
CHARACTER
INPUT
RETURN
WITH
CHAR IN liB"
ce
=)
NO ERROR
CS
=)
END OF MEDIA
(TIMEOUT)
GET
ADR OF FDB FOLLOWING
JSR
GET CONTENTS
OF FDB
GET
ADR
OF IOCB
SET END
OF MEDIA
STATUS
RETURN TO CALLER
GET ADR OF FDE FOLLOWING JSR
ADJUST STACK FOR RETURN
JUMP TO ADR FOLLOWING FDB
*
READER
INITIALIZATION ROUTINE
*
INITR
STX
LDX
CLR
CLR
LDAA
STAA
LDX
RTS
* *
INPUT ONE
"*
GETCP
STX
LDX
LDAA
LDAA
STAA
LDAA·
STAA
CLR
CLR
GETCl
LDAA
HR$CDB+CDEDDA
HR$CDB+CDBHAD
?TCTLJX
PTDTA,X
#$3C
PTCTLJX
SAVE
INDEX REGISTER
GET THE
PIA
ADDRESS
HR$CDE+CDBDDA
°
RESTORE INDEX REGISTER
CHARACTER
HR$CDB+CDBDDA
,SAVE THE INDEX REGISTER
HR$CDB+CDBHAD
.
GET THE
PIA
ADDRESS
PTDTA,X
CLR INTERRUPT
#$34
STROBE READER
PTCTLJ X
#$3C
PTCTL, X
HR$CDB+CDBWST
° °INIT THE TIMEOUT COUNTER
HR$CDB+CDBWST+l . AND CLEAR CARRY
PTCTL/X
°
READY TO READ?
Page
26-12
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