Atari 800 User Manual

216 User's Ha ndb oo k to the Atari 400 / 800 Co mput ers
Menu mu st be displayed
before a n ew com mand
ca n be e nt ered
DOS files ca n onl y be
written to Drive 1
NOTE/ POINT n ot avail-
ab le
for ran dom access
A m
ax imum of 3 files
ca n be open at any
one
time
Two Parts of Atari DOS
Menu need n ot be re-
displayed to ente r a
new com mand
DO S files ca n be written
to any drive
NOTE/ POINT sta tem ents
ava ilab le for ra ndom access
Up to 8 files ca n be
ope n at anyone time
Atari DOS co nsi sts of two different par ts . One part is us ed to save
and
load BASIC p ro grams and to read a nd w rit e data files. The
other part of Atari DOS consi sts of a gro up of utility programs
used in performing operat ions w ith disk fi l es as well as reading
a nd writing mac hin e language fil es.
In DO S version 1.0, both parts of DO S are stored as a single file
on di sk. This file is named DOS.SYS.
In DOS version 2.0, the two parts of DOS are stored on disk as
two separate program files. Th e first pa rt (DOS.SYS) is needed
whenever the disk driv e is being us ed . Th e second part
(DUP.SYS) is only required wh en the di sk uti liti es are being used.
By separating DOS in version 2.0, bett er use ca n be made of the
Atari 's memo r y. Onl y the part of DOS req uir ed need be l oaded
into memory. Th e portion of mem ory normally used by the
o
ther part of DO S is freed for use.

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