plotter stuff on that Brother printer

That Brother laser printer you bought can also pretend it’s a plotter. One of the requirements embedded in a PCL-compatible printer is an implementation of HP-GL/2. This is a slightly modified version of the page description language used by HP’s pen plotters. With care, you can make proofs on a laser printer.

Take, for example, this figure drawn in HP-GL:

It’s made up of familiar commands:

IN;SP1;PU4318,5988;
PD3971,5388,4664,5388,4318,5988;
PU4279,6026;
PD3957,5335,4716,5402,4279,6026;
 …

But add some magic header bytes (0x1b, 0x45, 0x1b, 0x25, 0x30, 0x42) and some trailer bytes (0x1b, 0x25, 0x30, 0x41, 0x1b, 0x45), and your printer understands it’s a PCL file.

The file, complete with header and trailer, is here:

You can print it like this:

lp -o raw hpgl-rotatey.hpgl

which produces a page like this:

HP-GL/2, on mono lasers at least, has some differences to the version used on plotters. The biggest difference is that there’s just one pen. You can change the pattern and line attributes of this pen, but you don’t get to change to multiple pens with different colours.

The manual for Brother’s HP-GL implementation lives here: Chapter 4: HP-GL/2 Graphics Language. Happy plotting!