Tandy 1000 User Manual

Basic
Video Pages
BASIC sets aside memory for the video display. The amount of
memory necessary depends on the screen mode you choose. BASIC
initially
sets 16K aside for video memory. You can change this with
the CLEAR statement.
Video memory is divided into pages. You can store information to
one page while displaying another. The amount of memory required
for each SCREEN mode is detailed in the following section.
Screen Modes
The color set and screen resolution are set using the SCREEN
command.
There
are 6 SCREEN modes as follows:
Screen Mode 0 (Text Mode)
Color Set: 16
Graphics Resolution: not available
Text Width: 40 or 80
Video
Page Size If WIDTH = 40, 2048 bytes
If WIDTH=80, 4096 bytes
Screen Mode 1
Color Set: 4 (2 palettes)
Graphics Resolution: medium resolution
Aspect Ratio: 516
Text Width: 40
Video
Page Size 16384 bytes
320
x 200
Screen Mode 2
Color Set: 2
Graphics Resolution: high resolution
Aspect Ratio:
5/12
Text Width:
80
Video
Page Size 16384 bytes
640 x 200
Tandy 1000
17

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