Technical Q&A QD11

LaserWriter 8 Local Customization File

Q: I have a PostScript Printer Description File (written to the Adobe PostScript Printer Description File Format Specification version 4.1 of 9 April, 1993), which works fine with the LaserWriter 8 driver (v 8.1.1) on a particular printer. I wrote a local customization file in the same format as the example on page 10 of the specification, which *Include's my valid PPD. I named that file "cust.ppd" and put it in "System Folder: Extensions: Printer Descriptions". I then selected LaserWriter 8 in the Chooser, selected my printer, selected Setup, selected Select PPD, and clicked on cust.ppd in the dialog box. At the bottom of the dialog box, I got the message "Does not appear to be a valid PostScript Printer Description file." Should the LaserWriter 8 driver accept a local customization file?

A: The Adobe documentation appears to be incorrect, in that the *Include example in the 4.1 specification incorrectly leaves out the following line:

	*PPD-Adobe: "4.1"

The LaserWriter 8 driver and the 4.1 PPD specification require that this line must always be the first line of a PPD file. Adding this line should solve the problem. In general, PPD developers should open the driver's 'PRFS' resource with ResEdit and turn on full PPD error messages (the driver includes a ResEdit template to make editing this resource easy) to help with debugging.