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

[BruceH]

(08-04-2020 09:45 AM)Martin Hepperle Wrote:  The background with the scaling factors is this:
The Tektronix terminals use a 12 bit integer range (0...4095) for x and y.

Since you are scaling, you could run your Tektronic in its 'backwards compatible' mode by sending the 4-character codes used by the previous 1024x1024 resolution model (which it should auto-detect). These are much simpler to calculate.

The following code expects X,Y on the stack in the range 0..1023 and uses list processing to speed up ordinary userRPL.

Code:

<< DUP ROT DUP 4 ->LIST R->B
{ 32 1 32 1 } / # 31d AND
{ 32 96 32 64 } ADD
B->R CHR  << + >> STREAM >>

The other option to consider would be to generate your coordinates as an N x 2 matrix or list and use list processing to calculate a string of N codes all at once. I'll see if I can adapt the above when I have a spare moment.