Hans, I think the "cut-away drawing of the space shuttle" was a demo .dxf file that came with AutoCad. Best Regards At 09:46 AM 8/22/03 +0200, you wrote:

It was. I'd suggest looking for an old copy of AutoCad. That will give you something to drive the plotters with and a bunch of interesting demo plots. I'm not sure if AutoCad used a dongle or not but check the docs and make sure that you get it if it requires it. FWIW I used to have a HP 7550 serial plotter connected to my PC. Windows 3.1 even had a printer driver for it. I could create text documents using MS Word and even highlight areas in it IN VARIOUS COLORS and then "print" it on the plotter. It was amazing to watch it write all the text. It would even switch pens automaticly to write the various colors of text. You couldn't use it for graphics with areas of solid colors but for line drawings, including text, it was fine. Joe At 04:05 AM 8/22/03 -0400, you wrote:

Hans, everyone has made great recommendations for file sources and various methods of translation. I have an additional alternative you might want to consider: writing your own driver program. I started my programming career working for a company that made digital mapping software, and wrote many plotter drivers (in Fortran IV even); they're generally pretty simple. HPGL in particular is dead easy. In fact, if you just connect to the plotter over the serial port using a comm program of some kind, you should be able to type the commands on the list below (very incomplete) to make things happen. With this information and a little more from web surfing, you can pretty easily translate any vector format into HPGL: SPn Select pen #n (on many you can SP0 to "unload" the pen carriage) PD Put the pen down (on the paper) PU Pick the pen up (off the paper) PAx,y Plot absolute-move to x,y; pen moves to absolute coordinate PRdx,dy Plot relative-move relative dx,dy from current position IN Initialize the plotter (resets scaling, etc.; some use DF instead) PG Eject the page (some models; roll feed may scroll) You can separate commands with a semicolon or CR/LF. So "IN;SP1;PU;PA1000,1000;PD;PR1000,0;PR0,1000;PR-1000,0;PR0,-1000;PU;PA0,0;PG" will draw a box. If memory serves, the default units of the plotter are 1/1000" of an inch, so this sequence would draw a 1" square box about 1" varies from model to model, as do its paper handling characteristics (and therefore its margins). Also be aware that some commands take longer to execute than others (a long line takes longer to draw than a short one), so your serial output should use handshaking if possible, may need to be slow if not possible--blasting a long plot out at 9600 will surely overrun the plotter and get you interesting results. If you have a LaserJet printer around, many can print HPGL directly (great for testing without burning up your pens). Just send ESC % 1 B (without spaces between) before the HPGL data. Send ESC % 1 A to get out of HPGL mode. I just tried on my LaserJet 4050, and it works fine. This, of course, is much more work than other suggestions people have made, but I myself am the sick sort that would consider this type of thing "fun". --Patrick