Apple II: LocalTalk ImageWriter Delay from BASIC (2/97)



I'm running an Apple IIGS lab (28 systems) with seven LocalTalk ImageWriters.

When using Applesoft BASIC, my computers print properly with a "PR#1" command. However, there is a 30-second delay from the time one computer finishes printing until the next system is allowed to print.

Here is a test program that I'm using:

10 PRINT CHR$(4);"PR#1"
20 FOR I=32 TO 126
30 PRINT CHR$(I);
40 NEXT:PRINT
50 PRINT CHR$(4);"PR#0"


If I run the above test program simultaneously on two Apple IIGS computers trying to print to one LocalTalk ImageWriter, the first computer to type "run" prints fine. The other computer has to wait for the LocalTalk option board to release the printer.

I have gone through the ImageWriter technical book and can't find anything that allows the LocalTalk card to release the printer Immediately after the "PR#0" command.

Is there a reset or release command that I can add to the program to eliminate this wait?


You are experiencing the time it takes the ImageWriter to release after the connection to the computer is lost. Your problem is that the "PR#0" command just changes the mode of the computer; the printer still thinks the first computer should be there.

The printer has a built-in timeout that can't be changed. Something you might try is to insert an "ESC c" as line 45. This command resets the printer and might cause the printer to drop its connection before the computer does.


Article Change History:
17 Feb 1997 - Reviewed for technical accuracy, revised formatting.
Published Date: Feb 18, 2012