PostScript Cartridge Plus for HP LaserJet III

The HP LaserJet III laser printer from 1990 used the Printer Command Language" PCL 5 by default, but could be upgraded with the HP PostScript Cartridge Plus" cartridge, which contained 2 MB of ROM with Adobe's PostScript Level 2 rasterizer. Let's look at the ROM contents and some of its hidden gems.

With how printers have become the butt of jokes, it's easy to forget they were sometimes kind of cool and had interesting technologies, features, and even expansions. The article has a follow-up, as well.