Atari 400 Technical Reference Manual page 19

1 INTRODUCTION
OENERAL DESCRIPTION OF THE ATARI HOME COMPUTER SYSTEM
Operating systems in the ATARI@ 400[TM] and ATARI 800[TM] Home
Computer are identical. The primary differences between the two
are:
o Physical packaging
o The ATARI 400 Computer console has one cartridge slot, the
ATARI 800 Computer console has two cartridge slots
o The ATARI 400 Home Computer contains 16K RAM and cannot be
expanded. The ATARI 800 Home Computer can be expanded to a
maximum of 48K RAM.
o The ATARI 800 Computer has a monitor Jack; the ATARI 400
Computer
does
not.
The Hardware Circuit~y
o Produces both character and point graphics for black and
white (B/W) or color television.
o Produces four independent audio channels (frequency
controlled) which use the television sound system.
o Provides one bi-level audio output in the base unit.
o Interfaces with up to four Joysticks and eight Paddle
Controllers.
o Interfaces with a serial
lID
bus for expansion.
o Contains a built-in keyboard
Figure 1-1 presents
a
simplified block diagram of the hardware.
See the hardware manual for supporting documentation.
OPERATING SYSTEM C016555 -- Section 1
18