Commodore Plus 4 - Page 97

BASIC Version 3.8 Commands, Functions, and System Variables 85
The SCALE command lets you change these values to 1024 logical dots both
across and down in any mode.
In particular, this is useful when you are unsure whether a final program will
run in high-resolution or in multicolor mode. If you do all the drawing with
SCALE on, the figures will be the same size in either mode. No coordinate
transformations are required to move between high resolution and multicolor
SCALEd coordinates.
The SCALE command may be executed at any time and remains in effect until
canceled.
After you turn on scaling, you must adapt the drawing commands to the new
screen coordinates. For example, the center of the high-res screen is no longer
160,100. It is now 512,512.
To calculate SCALEd values from high resolution or multicolor coordinates,
use these formulas:
High-res rows 5.12 * row coordinate
High-res columns 3.2 * column coordinate
Multicolor rows 5.12 * row coordinate
Multicolor columns 6.4 * column coordinate
For example, to get the same circle as drawn without SCALE by
CIRCLE, 160,100,60,50, you can use the following lines with SCALE:
5 SCALE 1
10 A = 3.2 * 160: B = 5.1S * 100
20 C = 3.2 * 60: D = 5.12 * 50
30 GRAPHIC 2,1
40 CIRCLEA3,C,D
Parameter: on or off
Turn SCALEing on by using the parameter 1. Turn SCALEing off with the
parameter 0.
SCNCLR Abbr.sC
Erases the screen and returns the cursor to the top of the screen or text area.
Use SCNCLR to clear the screen in any mode, text or graphic.
SCRATCH Abbr. scR
SCRATCH file name, Ddrive, Uunit
Deletes a disk file permanently. References to the file are erased from the disk