I found an FP-215 plotter at a yard sale years ago, and I had many ideas about what I could do with it. Like many ideas of my ideas, it never got further than a couple of "hello world" types of tests. After moving a couple of times, I finally gave the plotter away for free to a random person on the internet. I hope it got used for an interesting project.
This is all the information I found about the plotter, and it seems a lot of these resources are now gone. Hopefully, these resources will be helpful to somebody else. Do not hesitate to drop me a line to let me know what you're using the plotter for! Who knows, maybe I'll even list your project here.
The following information was mirrored from the following URL which no longer exists.
http://www.geocities.com/maboytim/fp215/
The native plotting language of the FP-215 is quite simple - I call it RSGL (Radio Shack Graphics Language for lack of a better term). The best way to control the FP-215 is to use a utility (filter) to convert from some well supported graphics language, such as HPGL, to RSGL.
As mentioned, RSGL is pretty simple - the only necessary commands are Move (move with pen up) and Draw (move with pen down).
I don't know much about HPGL but I'm sure it's more complicated and capable than RSGL - but ultimately, the plotter's job is to draw on the paper so any plotter command stream can in principle be converted to a sequence of Move and Draw commands. In addition, there's nothing that says an application or driver has to use the full capability of HPGL and if the application or driver uses only (the equivalent of) moves and draws the conversion from HPGL to RSGL can be trivial. In fact, the AutoCAD HP7550A plotter driver seems to use only Moves and Draws (AutoCAD is essentially the only application I use with the FP-215 although others are possible - Windows for example has an HP7550A print driver although I don't know how restrictive a subset of HPGL it uses).
HPGL uses PenUp (PU), PenDown (PD), and PenAt (PA) commands - a Move is a PenAt with the pen up, a Draw is a PenAt with the pen down.
RSplot is a conversion utility written in C. It supports only the PU, PD. PA, and SP (SelectPen) commands. Multiple pens are supported by generating an output file per pen - this allows the FP-215's pen to be manually changed between colors. RSplot can be easily extended to include additional HPGL commands as needed but these four simple commands are sufficient to convert AutoCAD HPGL plot files.
RSplot was written for DOS and compiled using PowerC. It should be easy to port to other environments.
drawRSGL is a small Gtk-Perl script for Linux derived from drawHPGL (an HPGL previewer by Henry Palonen).
Sample RSGL plots.
Sample HPGL plots.
The original fp-215 manual, scanned to .gif and .jpg files.
Mirrored information about the fp-215 from radioshack.com