Atari 400 User Manual

218 Us er's Handbook to the Atari 400/ 800 Co mputers
5. If you are booting DO Sversion 2.0on a system with a BASIC
ROM ca rtridge in sta lled, th e BASIC prompt READY will
appear on the video display. By e nt ering the following
command at the keyboard,
the DOS Menu will be loaded.
In step 5, DOS .SYS is loaded during the initial part of the loading
proc ess. When the DOS statement is ex ec ut ed , DUP. SYS will be
loaded in
to m emo ry.
In DOS version 2.0, DUP.SYS is loaded into an area of me mory
where B AS IC programs are stored. When DUP.SYS is lo a ded, any
existing
BASIC program in mem ory will be erased .
In DOS ve rs ion 1.0 the disk utilit y package is contained in the
DOS .S YS file . DOS .SYS does not overw rite the ar ea in RAM
where BASIC programs are s tor ed. Therefore , load ing DOS
version 1.0 will not affect a B AS IC program in m emo r y.
DOS Menu
The DO S M e nu lo aded depends on the version of DOS us ed.
The
DO S Menu loaded by DO S versi on 1.0 is depicted in
Illustr ation 7-7. Th e DOS Menu loaded by DO S version 2.0 is
pictur ed in Illu st rati on 7-8.

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)