Since I upgraded my Slackware-based system from 13.37 to 14, my parallel-port HP Deskjet 815C has stopped working. Cups registers jobs as printing successfully but the printer doesn't actually do anything. It's Slackware-specific as the printer still works under AntiX.

The software versions are:
Slackware: cups-1.5.4 and hplip-3.12.9 plus foomatic-filters
AntiX: cups-1.5.3 and hplip-3.12.6

hp-check in Slack shows that this build of the hplip toolkit doesn't support parallel ports but I understand from googling that the hpijs driver itself should still do so.