Atari 400 Service Manual

Figure 3-2. Special Graphics Using the CTRL Key
• RETURN - The RETURN key has three functions. First, if moves the
cursor to the left margin and down one line on the screen. Second,
RETURN marks the end of a logical line for the computer. Third,
RETURN activates the computer. The specific action taken depends on
the software.
• CLR-SET-TAB - This key operates much like the TAB key on a regular
typewriter. SHIFT and CLR-SET-TAB set a TAB stop at the cursor
position. CTRL and CLR-SET-TAB clear the TAB stop u nder the
cursor. CLR-SET-TAB by itself spaces the cursor over to the next
TAB stop. This key operates on logical lines so you can tab at any
position up to the 116 th character.
3-4 System Service Manual

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)