FNCTPLOT.BAS
        ============

A X/Y-function plotter which plots a mathematical function on the 
display. (Author: Puehringer Edgar)

Start:
RUN or RUN "PLOT"

Usage: 
The program draws a X/Y-function plot on the screen of the PC-1280. 
It respects the gap between the characters and the two lines (equalised
output). You should place your custom function in e.g. line 100 and give
it the label "FNKT". Don't forget the RETURN! The function must calculate 
Y (output) from X (input). There are three configuration screens, you can 
navigate through the screens using "C" (continue) and "B" (back). The 
screens are:

X Range configuration:
----------------------

Just specify X1 and X2, the screen is self explaining.

Y Range configuration:
----------------------

Just specify Y1 and Y2, the screen is self explaining.

Axis configuration:
-------------------

Here you can configure if the X and Y axis are visible. Just toggle with 
"X" and "Y". If zero is out of the range X1 ... X2 (or Y1 ... Y2) then 
"OS" (off screen) is displayed. If the Y axis is in the gap between the 
lines or the Y axis is between two characters, then "IV" (invisible) is 
displayed. In this case, move back to the X or Y configuration screen and 
select other values.

While plotting is in progress, you may cancel by pressing "C-CE" for a few seconds.

The pre- written demo function looks very nice with:

X1 = -360   X2 = 360 (DEGREE mode)
Y1 = -0.9   Y2 = 1.3

with both axis turned on. Just have patience, it takes a few seconds!

Graphics        : **
Sound           : *
Libraries needed: none