Atari 800 User Manual

86 User's H andbook to the Atari 400 /8 00 Computers
A tab stop ca n be cleared in the imm ediate mode by moving the
cu rsor to the position desired and then pressing CTRL-TAB. In
the program mode, a tab stop can be cleared by moving to the
des ir ed co lumn and displaying ASCI I 158 . This code ca n be be
displayed e ith er w ith the CHR$ functi on or with ESC / CTRL-T AB.
One final point to keep in mind about tabstops is that w hen ever
a character is output in the space i mmediate ly prec ed ing a tab
stop, that tab
stop no l onger has any effect .
Moving the Cursor with Escape Sequences
As mentioned earli er in this ch apter , the c ursor can be m oved by
using the escape sequences
for cursor co ntrol key sequence
within a PRINT statement s tring . For examp l e, in the following
statement,
100 PRINT" - - J OHN JOHNSON"
the symbo l - repr ese nt s pressing the fo ll owi ng key seq uence:
ESC / CTRL-*
This key seq uence causes
the c ur sor to move one position to the
left each t im e it is pr esse d.
Cursor contro l escape seq uences can also be includ ed in a
PRINT statement string by using th e ASCI I code for that
sequence with the ASC$ function. For exa mple, in the following
statemen ts,
100 DIM A$(10)
200 A$ = CHR$(29)
300 PRINT A$:PR INT A$:PR INT A$
the st ri ng variable A$ is set to the ASCI I code for c ur so r dow n. In
lin e 300, the three PRINT statements ca u se the cursor to be
moved down 3 lin es.
These c ur so r contro l sequen ces do not erase any of the
characters that they pass over.

Atari 800 Specifications

General

Processor	MOS Technology 6502
Processor Speed	1.79 MHz
ROM	10 KB
Graphics	ANTIC and GTIA chips
Release Year	1979
Display Resolution	up to 320 x 192
Colors	128 colors
Sound	4 channels
Storage	Cartridge, cassette, floppy disk
Ports	Cartridge, serial, monitor
Operating System	Atari OS