QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Printer support in Photon |
| Ref. No. |
QNX.000006272 |
| Category(ies) |
Utilities |
| Issue |
We are trying to make Pp.pcl working properly with our printer (HP Laser Jet III). The idea is to send PHS output to the lpsrvr which has to use an appropriate filter for the data output. It makes the Photon printing procedure more unified, unless having the lpsrvr on a computer that is especially dedicated for printing.
Usually, this computer is not expected to be "wore" in the Photon stuff [Pp.*, phfont and etc.]. In my company the lpsrvr works on an i386 with 8M RAM (and does it perfectly). But when I decide to print out a Photon screen with 600 dpi resolution it takes about 30-40 minutes. Moreover we're forced to have an extra Photon licence on the lpsrvr computer.
I'd like to suggest to add some option to the printer library that allows the PHS output to be converted to the PCL format on the local computer (like it does when printing to a file). In this case I don't need to start any of the Photon applications on the lpsrvr computer but use it as the spooler only.
The second issue is about PCL output quality produced by Pp.pcl. I've realized that Pp.pcl tries to make all color conversions itself. It just calculates corresponding patterns for every color. It would be more preferably to use native HP gray scale patterns for colors occurred in PHS.
Also, it would be useful to manage the native or software fonts instead converting symbols to bitmap. Is there a possibility to give us description of the PHS format. Having this description we could write our own converters as for PCL as for some obsolete printers that our customers use.
|
| Solution |
1) If you send your output to a 'Filename' rather than a 'Device' then photon does the conversion for you before writing it.[This makes VERY LARGE files ofcourse]
You can the write the file to a /dev/spool/hp-raw device.
2) The idea of letting the printer do this does not work for technical reasons. The draw stream draws various colors, at random times. HP-PCL5 only allows colors to get darker, not lighter.
Therefore things do not mesh well.
That's why HP came out with PCL-6/PCL-XL.
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