I’ve got an old but still perfectly working Xerox printer on my network. Existing computers can connect to it with full functionality. When adding the printer to a new computer, there is a “Use:” menu which offers
Generic Postscript Printer
Generic PCL Printer
Previously the routine was to choose “Other…” and then select a Printer Description File, a postscript file supplied by Xerox.
But now when I try to set it up on a new computer, and try to select this printer description file, the file is greyed out in the file selector.
Existing computers where the printer is already set up, still work with it even though their version of macOS has been updated. Even a new computer, with user migrated from an older one, has the migrated printer definition working fine. But if trying to to add it as a new printer it’s not possible to select this file, and so not possible to set it up properly. I can still set up the printer as a generic printer, but can’t then access all the features.
Does anyone know what the printer set up software is looking for when it decides whether to allow me to select the printer description file? Does it need a particular extension (I’ve tried .ppd and .PPD) ?