Tandy 1000 Basic Reference Manual

Chapter 10 I BASIC Keywords
PRESET produces an opposite image on the screen. With 2
color sets, white becomes black on the screen. With 4 and
16 color sets, the color value becomes the numeric opposite
on the screen. This table shows the color displayed for each
possible value:
16 color
4 color
Array Screen
Array Screen
Value Color
Value Color
0 3 0 15
1 2 1 14
2
1 2 13
3 0
3 12
4 11
5 10
6 9
7 8
8 7
9 6
10 5
11 4
12 3
13 2
14
1
15 0
AND transfers the image over existing image. The result is
a logical AND
of the array and the image on the screen.
OR superimposes an image onto an existing image. The re-
sult is
a logical OR of the array and the image on the
screen.
XOR inverts the points on the screen where a point exists
in the array image. When an image is PUT against a com-
plex background twice, the background
is restored un-
changed. This lets you move an object around the screen
without obliterating the background.
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Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200