2 ms·

I was using a CP/M computer - there was no driver architecture. You sent HP-GL instructions and data as text via the RS232 interface. The plotter obviously had

• rahimnathwani 6y ago
  So interesting! In the most recent reference guide I found just now, it seems you can draw a segment of a pie chart using a single EW (Edge Wedge) instruction but, for a complete pie chart, this method would require you to calculate the angles of each segment yourself. And of course to add the labels yourself. Perhaps I'm looking in the wrong place or perhaps the instruction to draw a whole pie chart has been deprecated.
  • zabzonk 6y ago
    You may be right - this was a looong time ago. Calculating the angles from the data is not difficult though, so I may have forgot that I did it. I can't really imagine calculating and placing the labels myself though, but perhaps I was cleverer then! Anyway, the HP pen plotter we had in the early 1980s was a very impressive device, when what we had were Z80 based computers driving them.
    • joshu 6y ago
      You misremember. It doesn't do any of that.
• yjftsjthsd-h 6y ago
  > The plotter obviously had a limited buffer size, which would prevent certain optimisations, but then so did the CP/M computer! Yeah, but which had more? :) Reminds me of that time in the 90s(?) when people connected printers to computers, but the printers had more powerful processors than the computers. (Or later, when someone poked into the WiFi board on their arduino and realized that it was a more powerful microcontroller, but that's not so directly related)