Installation guide

In addition, printing non-PostScript files with some PostScript and
non-PostScript filters may yield unexpected results. Table 10–9 lists the
filters with which you could experience these problems.
Table 10–9: Non-PostScript and PostScript Filters
Filter Name Filter Type
lpf Non-PostScript
la75of Non-PostScript
la324of Non-PostScript
lqf Non-PostScript
hplaserof PostScript
To provide expected behavior with older printers, these non-PostScript
filters maintain a dependence on the serial port driver to automatically
supply carriage returns after line feeds when you specify the (octal) 020 bit
to the
fs control variable in the /etc/printcap file.
Because this control bit is not interpreted by the network socket driver, the
formatting behavior that would be supplied by the serial port driver is
absent. Therefore, non-PostScript files that are not formatted for the
printer may not print out as they would in serial-port-connected
configurations. In particular, this may affect ASCII text files that do not
contain embedded carriage-returns.
Most printers using the lpf, la75of, la324of, and lqf non-PostScript
filters do not provide network interface card support. However, the printing
problems may still be an issue for users who use serial-and-parallel-port to
network-port converters, like the Compaq(Digital) RapidPrint network
interface box, which allow these printers to act like TCP/IP printers with
built-in network support.
The hplaser4psof PostScript filter works for PostScript files and for
preformatted non-Postscript files (like PCL files), but it will likely produce
unexpected results for files that have not been preformatted (such as ASCII
text without embedded carriage-returns).
Administering the Print Services 10–35