HP 2100 Series - Page 52

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Examples of the trace formats follow:
>>LPT cmd: Printed 136 characters on line 1
>>LPT cmd: Printer commanded to slew to VFU channel 3 from line 1
>>LPT cmd: Printer advanced 1 line to line 2
>>LPT csrw: Control is character | '#'
>>LPT csrw: Status is online | ready | VFU 12 | idle
>>LPT serv: Unit delay 1577 service scheduled
>>LPT serv: Printer service entered
>>LPT xfer: Character 'G' sent to printer
>>LPT xfer: Format code 102 sent to printer
>>LPT iobus: Received data 000000 with signals STC | CLF
>>LPT iobus: Returned data 000000
The Line Printer Controller state contains these registers:
Name Size Radix Symbolic Read-Only Description
DEVCTL
1 2 Device control flip-flop
DEVFLG
1 2 Device flag flip-flop
DEVFBF
1 2 Device flag buffer flip-flop
STROBE
1 2 Strobe signal to the printer
DEMAND
1 2 Demand signal from the printer
OUTPUT
16 8

Output data word to the printer
STATUS
16 8 Device status from the printer
PFAULT
1 2 Paper fault exists
TFAULT
1 2 Tape fault exists
OLPEND
1 2 Offline transition is pending
PRLINE
8 10 Current print line number
BUFIDX
8 10 Current print buffer index
PRTBUF [0:423]
88

Print buffer
OVPCHR
88

Overprint character
FORMLN
810

Form length in lines
VFU [0:144]
12 2

Vertical format unit channels
PUNCHR
88

Punched channel character
UNPCHR
88

Unpunched channel character
BTIME
24 10 Fast printer buffer load delay time
PTIME
24 10 Fast printing delay time
STIME
24 10 Fast paper slew per-line delay time
POS
32 10 Printer file current position
The PRTBUF, OVPCHR, PUNCHR, and UNPCHR registers default to single-character format display and entry but
may be overridden with numeric-format switches, if desired. The OUTPUT register defaults to octal display but
may be displayed in single-character format by specifying the –A switch. Symbolic entry for this register is also
supported.
The PFAULT and TFAULT registers indicate a paper fault and a tape fault, respectively, when they contain the
value 1. Attaching the printer will clear a paper fault. Setting the printer online will clear a tape fault.
The character used to represent an overprinted position may be changed by depositing a new value into the
OVPCHR register. For example, the DEPOSIT LPT OVPCHR @ command will change the character from the
default DEL (octal 177) to the commercial-at sign (octal 100). Similarly, the characters used to represent punched