Atari 800 User Manual

Atari 810 Disk Drive 217
Disk Buffer
Atari DOS controls the transfer of information between the Atari
computer and the disk drive. Information is transferred in 128
cha racter
blocks.
Four separate portions of Atari RAM are set aside to hold data
being transferred to a di sk from a disk drive.These are known as
disk buffers. The reason why there are four disk buffers is that as
many as four disk drives can be attached to the Atari at anyone
time .
When Atari DOS is instructed to supply data, it will first attempt
to supply this data from the disk buffer. When the buffer runs out
of data, another block of data will be read into the buffer from
the diskette .
Data
is also written to disk e tte from the disk buffer one block at a
time. Information that is to be transferred to disk is first sent to
the disk buffer. When the disk buffer has been filled , Atari DOS
writes the data in the buffer to the diskette.
Booting DOS
Before Atari DOS is available for usage, it must be loaded into
memory from a diskette . This process is known as booting DOS.
The procedure for booting DOS is as follows:
1. Power on Drive 1. If your sys tem includes more than one
drive, Drive 1 can be determined by examining the access
hole on the back of each drive. On Drive 1, both the black
and white switches are located to the far left.
2. Insert a diskette containing a copy of DOS into Drive 1.
3. Turn the Atari 400 or 800's power off (if necessary) and on.
4. If you are booting DOS version 1.0 or if you are booting
DOS version 2.0 on a system without a BASIC ROM
cartridge installed, the DOS Menu will appear on the video
display.

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