Speed of HP-49G Routine for Tektronix Vector Graphics Terminal

[Martin Hepperle]

Thank you very much for your ideas and solutions!

Especially the SysRPL version seems to be the most attractive to me.
I also toyed a bit with SysRPL (I must be considered a perfect noob in this black art) but ended up only with a 25% improvement in speed. But I used many conversions to HXS numbers to get bitOr and bitAnd, which was unnecessary. And it took me 2 hours to learn that I need a "11" or "REALREAL" at the start of the routine instead of the "BINT1" I had...

The background with the scaling factors is this:
The Tektronix terminals use a 12 bit integer range (0...4095) for x and y.
In my practical application I have to scale from my arbitrary, real valued user coordinate system to this integer range.
That's why in my example case I used 1500 and 10 as scaling factors. In real life these factors depend on the data range to be plotted and they are always needed.
[For real-world scaling the x-values would be scaled by 4095*(x-xMin)/(xMax-xMin) for full a width plot].

However, in the end everything goes through the serial interface at 9600 baud, so there are more speed limits in the chain. The end result is that the HP 48/49 can send vector graphics to an external display (a hardware terminal or software emulator like Windows TeraTerm).

Martin