Atari 400 Hardware Manual

Mixing
Graphics Modes,
cont.
TABLE Ill
MODE BYTE
~
<
I
~
I
SCAN
I I I
I
LEFT
I
RIGHT c.c. I
LINES!
I I
RAM
REMARK! NIBBLE!
NIBBLE PER
I
PER tl
I
MODE!
PER
I
(HEX)
I
(HEX)
PIXEL!
MODE
COLORS!
I
LINE
I I
LINE
I
I
I
I
2
~
8 l \
0!
0
I
40
CD
I
4
I
CHAR
3
~
10
l ~
I I
40
I
4 1 8 4
I
I
40
I
MODES 5 1 16 4
I
40
G)
0
I
6 l 8 5 1
I
20
I
7 1 16 5 2
I
20
I
8 4 8 4
3
I
10
I
I
9
2
4
2 4
I
10
CD
4 \GRAPHIC! A
2 4 4 5
I
20
I
B 1 2
2 6
I
20
I I
MODES
c
1 1 2
I
20
I I
D l 2
4
7
I
40
0
I
0
I
E
1
1
4
I
40
I I
F
\
1
1
~
8
I
40
BLANK!
0-7
I
@
0
BLANK I
I
JUMP
I
4
!SPECIAL
1
JUMP
I
I
CD
When the max RAM mode is not at the top of the screen,
the
left nibble of the LMS byte must be changed to a
4.
Left nibble for all mode bytes after the LMS byte.
0
Color & Lum for the field is controlled by Setcolor 2, and
Lum for characters or graphics from Setcolor 1.
JUMP - used to end the display list and return to the
beginning.
BLANK - to output selected number of background lines.
B -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)