kv56962@tut.fi (V{{r{nen Kari) (11/09/89)
We have found a problem with a HP7600 series electrostatic plotter. If you send another drawing to it while it is still drawing the previous one, it forgets to draw some vectors. We are using Centronics cable to connect our Sun 386i to it. I suppose the handshakes are ok, because all pictures are drawn correctly if sent there on their own. I contacted the Hewlett Packard of Finland, but they told me that their hardware never has any faults... :-) Will you, please, email me. I'll summarize if needed... -- SO LONG AND THANKS FOR ALL THE FISH (The dolphins) Kari Vaaranen Tampere University of Technology Majakkakatu 30, kv56962@tut.fi SF-33410 Tampere, FINLAND (These opinions are mine and mine ONLY!)
mark@hp-sdd.hp.com (Mark Overton) (11/09/89)
In article <KV56962.89Nov8203208@naakka.tut.fi> kv56962@tut.fi (V{{r{nen Kari) writes: | |We have found a problem with a HP7600 series electrostatic plotter. If |you send another drawing to it while it is still drawing the previous |one, it forgets to draw some vectors. | |We are using Centronics cable to connect our Sun 386i to it. I suppose |the handshakes are ok, because all pictures are drawn correctly if |sent there on their own. Email bounced, so ... Hi, I'm one of the engineers who wrote the firmware for that plotter. My prior plotter was the original 7585A, so I'm afraid I don't know much about everything else. Anyway, it sounds like you are sending one of the following escape sequences to the plotter: ESC.J, ESC.K or ESC.T These sequences are "immediate execute" meaning that they are performed immediately upon their arrival. However, if plotting is occuring, the action of these sequences is delayed until plotting is done. Some of these sequences clear the input buffer. So when their action is delayed, the input buffer will be cleared, and you'll lose any data you sent after the ESC. stuff. These sequences are intended for two-way communication environments so that you can tell when the prior plot is done before sending the above sequences. Unfortunately, Centronics is only one-way. So the solution is to ELIMINATE ESCAPE SEQUENCES FROM YOUR PLOTS. They usually aren't necessary except to set-up handshake protocols, which are not needed for Centronics. BTW, you can call one of HP's customer support centers (not sales offices) to get help with problems such as this one. Hope that cures the problem ... Mark Overton, Hewlett-Packard (San Diego Div) (619)-592-4732 ...hplabs!hp-sdd!mark from {allegra|decvax|gatech|sun|tektronix} or ...hp-sdd!mark from {hp-pcd|hpfcla|hpda|noscvax|gould9|ucsd}