Xerox 530 And Sigma 2/3 Programming Example - Xerox 7120 Reference Manual

XEROX 530 AND SIGMA 2/3 PROGRAMMING EXAMPLE
The following coding sequence illustrates a card reader routine for use with Xerox
530
and Sigma
2/3
computers.
The routine performs a read operation and returns to the main program. The calling sequence is:
Label
P
L
X
A
READ
ERROR
RETURN
ORDERLOC
IOCD1
IOCD2
LDX
LDA
RCPYl
BUFFER
ORDER
P, L
B READ
RETURN LOCATION
Command
EQU
EQU
EQU
EQU
STA
RCPY
5TA
LDA
WD
LDA
WD
LDA
510
TIO
BNC
B
RD
BAN
RD
AND
BAZ
RCPY
RCPY
RES
RES
DATA
LPOOL
Argument
2
4
7
ORDERLOC
X,A
IOCD1
=ORDERLOC
X'E '
=X '
4001 1
X'F '
=3
$+2
$-2
X'F '
ERROR
X'E '
=X '
8800 '
RETURN
*O,A
L, P
120
X = Address of input buffer
A = Card reader order code
Comments
Define P register.
Define L register.
Defi ne X register.
Define A register.
Store order code.
Store buffer address.
Load address of order into
even-numbered channel register.
Odd -numbered channel register.
Set to data chai n
wi
th byte count = 1.
Devi ce number of card reader.
Start input.
Test input.
Branch if input complete.
Branch if input not complete.
Check for val idity error.
Branch if validity error.
Check for transmission error
or unusual end.
Branch if no error or unusual end.
Set A register to -1 (error code).
Return to main program.
Set to A register value on entry.
Set to X register val ue on entry.
Byte count (no data chai ni ng).
Allocate literals.
Appendix B 23