Printer Control

The LISTPTR command can interrogate the condition of printers and communicate the results to a Proc. The command displays:

The location in the Spooler where the desired printer is available. It is available:

For example, after executing the LISTPTR command, the following contents are found in the secondary input buffer:

1134 1171 1 0 4 127 0

These values can be translated as follows:

1134	Buffer contents resulting from LISTPTR command.
1171	Printer is inactive.
1	Printer number 1.
0	First output queue, in this case 0.
4	Second output queue, in this case 4.
127	Specifies no queue, and is internal flag.
0	Page skip specification.

The following Procs shows how to execute the STOPPTR, LISTPTR, and STARTPTR commands under the control of PROC.

PROC	Description
HSTOPPTR 3	Issue a stop command.
P	Execute it.
SS	To the secondary input buffer.
B	Back up input pointer.
5 IF # A G 20	Out of data.
IF A = 1171 G 80	Stopped and inactive, go to start.
IF A = 1174 G 80	Unallocated, go to start.
IF A = 1172 G 15	Pause.
F	To next buffer element.
G 5	Test next.
15 HSLEEP 1	Pause.
20 HLISTPTR 3	Execute the LISTPTR command.
P	Issue the LISTPTR command.
SS	Set the pointer to the secondary input buffer.
B	Back up input buffer pointer.
25 IF A = 1034 G 10	Check for the correct initial mark.
IF # A G 99	Not there.
F	To the next element.
G 25	Test it.
10 F	To the condition.
IF # A G 99	Nothing there.
IF A = 1074 G 80	Not allocated, can be used.
IF A = 1171 G 80	Inactive, go start.
IF A = 1172 G 40	Active.
C THE BUFFER CONTAINS ILLEGAL DATA.
XBAD DATA.	Error exit.
40 OTHER PRINTER IS ACTIVE: DO YOU WISH TO WAIT (Y/N)+
SP	Set the pointer to the primary input buffer.
IP?	Input the answer.
IF A = Y G 15	Pause.
X TCL	Else exit.
80 HSTARTPTR 3,7,0,S9	Start the printer.
P	Execute the command.