Jan 202013

Many moons ago, we acquired an old RolandDG DXY-800A plotter.  This is an early A3 plotter which took 8 pens, driven via either the parallel port or the serial port.

It came with software to use with an old DOS-version of AutoCAD.  I also remember using it with QBasic.  We had the handbook, still do, somewhere, if only I could lay my hands on it.  Either that, or on the QBasic code I used to use with the thing, as that QBasic code did exercise most of the functionality.

Today I dusted it off, wondering if I could get it working again.  I had a look around.  The thing was not difficult to drive from what I recalled, and indeed, I found the first pointer in a small configuration file for Eagle PCB.

The magic commands:

H Go home
Jn Select Pen n (1..8)
Mxxxx,yyyy Move (with pen up) to position xxx.x, yyy.y mm from lower left corner.
Dxxxx,yyyy Draw (with pen down) a line to position xxx.x, yyy.y mm

Okay, this misses the text features, drawing circles and hatching, but it’s a good start.  Everything else can be emulated with the above anyway.  Something I’d have to do, since there was only one font, and I seem to recall, no ability to draw ellipses.

Inkscape has the ability to export HPGL, so I had a look at what the format looks like.  Turns out, the two are really easy to convert, and Inkscape HPGL is entirely line drawing commands.

hpgl2roland.pl is a quick and nasty script which takes Inkscape-generated HPGL, and outputs RolandDG plotter language. It’s crude, only understands a small subset of HPGL, but it’s a start.

It can be used as follows:

$ perl hpgl2roland.pl < drawing.hpgl > /dev/lp0