GSXTEST performs basic tests on a GSX driver - drawing simple shapes, changing colours and write modes, etc. It's intended to help with driver development by providing a simple way to test various functions.
Buildable source for the three Epson printer drivers (DDFXHR8, DDFXLR8 and DDFXLR7) based on the published source for the MX80 driver at bitsavers.org.