Specifications

5-13
Troubleshooting the Base Operating System Spooler
Considerations for 8–Bit Printer Attached to 7–Bit Interface
Some printers assume an 8–bit (8 bits per byte) interface to the host. Although an 8–bit
printer may print when attached to a 7–bit interface, the printed output may not be
acceptable. To determine if your printer assumes an 8–bit interface, consult your printer
manual.
Incorrect printed output can be produced in the following situations:
• Printer command sequences may contain 8–bit values.
If an 8–bit printer must be attached to a 7–bit interface, follow this procedure to prevent
incorrect printed output.
1. Enter the SMIT fast path smit lsvirprt.
2. Select the print queue and enter:
j=!j=!
3. Press the Enter key to exit.
This prevents print file initialization strings, which may contain 8–bit command
sequences, from being sent to the printer.
Note: This also bypasses printer initialization. So, depending on the pitch, line
spacing, and other attributes left by the previous print file, the output may not print
correctly.
• Printer character code points may be 8–bit values where each graphical character is
represented by an 8–bit integer value causing the wrong character to be printed. To
avoid this problem, all the characters in the print files should be in the portable ASCII
character set.
• Printed graphic files are affected when a 7–bit interface is used because some of the
data points are lost.