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Reference cards


Graphics modes

BASIC mode(dec)
Antic mode(hex)
# of colors
Resolution + display mode
Scan lines per mode line
Screen memory (bytes)
Bytes per line
Bits per pixel
0
2
2
40x24 (text)
8
960
40
8
-
3
2
40x24 (text)
10
760
40
8
1
6
5
20 x 24 (text)
8
480
20
8
2
7
5
20 x 12 (text)
16
240
20
8
3
8
4
40x24 (graphics)
8
240
10
2
4
9
2
80 x 48 (graphics)
4
480
10
1
5
A
4
80 x 48 (graphics)
4
960
20
2
6
B
2
160 x 96 (graphics)
2
1920
20
1
7
D
4
160 x 96 (graphics)
2
3840
40
2
8
F
2
320x192 (graphics)
1
7680
40
1
9
F
16
80x192 (graphics)
1
7680
40
4
10
F
9
80x192 (graphics)
1
7680
40
4
11
F
16
80x192 (graphics)
1
7680
40
4
12
4
5
40x24 (text)
8
960
40
8
13
5
5
40x12 (text)
16
480
40
8
14
C
2
160x192 (graphics)
1
3840
20
1
15
E
4
160x192 (graphics)
1
7680
40
2

Text modes


BASIC mode 0 (ANTIC mode 2)
40 x 24, 2 colors 		BASIC mode 1 (ANTIC mode 6)
20 x 24, 5 colors 		BASIC mode 2 (ANTIC mode 7)
20 x 12, 5 colors
BASIC mode 12 (ANTIC mode 4)
40 x 24, 5 colors 		BASIC mode 13 (ANTIC mode 4)
40 x 12, 5 colors

Graphics modes

BASIC mode 3 (ANTIC mode 8)
40 x 24, 4 colors 		BASIC mode 4 (ANTIC mode 9)
80 x 48, 2 colors 		BASIC mode 5 (ANTIC mode A)
80 x 48, 4 colors
BASIC mode 6 (ANTIC mode B)
160 x 96, 2 colors 		BASIC mode 7 (ANTIC mode D)
160 x 96, 4 colors 		BASIC mode 8 (ANTIC mode F)
320 x 192, 2 colors
BASIC mode 9 (ANTIC mode F)
80 x 192, 16 colors 		BASIC mode 10 (ANTIC mode F)
80 x 192, 9 colors 		BASIC mode 11 (ANTIC mode F)
80 x 192, 16 colors
BASIC mode 14 (ANTIC mode C)
160 x 192, 2 colors 		BASIC mode 15 (ANTIC mode E)
160 x 192, 4 colors

ANTIC

ANTIC ("Alpha-Numeric Television Interface Circuit") is a microprocessor dedicated to the television display. It is a true microprocessor; it has an instruction set, a program (called the display list), and data. The display list and the display data are written into RAM by the 6502. ANTIC retrieves this information from RAM using direct memory access (DMA). It processes the higher level instructions in the display list and translates these instructions into a real-time stream of simple instructions to GTIA.

CTIA/GTIA

CTIA ("Color Television Interface Adapter") / GTIA ("George's Television Interface Adapter") is a television interface chip. ANTIC directly controls most of GTIA's operations, but the 6502 can be programmed to intercede and control some or all of GTIA's functions. GTIA converts the digital commands from ANTIC (or the 6502) into the signal that goes to the television. GTIA also adds some factors of its own, such as color values, player-missile graphics, and collision detection. Early 400/800 models included CTIA, later 400/800 models and all later 8-bit Ataris included GTIA. In BASIC, type POKE 623,64 [RETURN] and if the screen blackens, you have the GTIA chip. If it stays blue, you have the old CTIA chip. By the way, apparently no CTIA-equipped Ataris were shipped to Europe.

References

https://www.atariarchives.org/dere/chapt02.php
https://www.atariarchives.org/mapping/appendix8.php
https://hintermueller.de/dereatari-chapter-2
https://www.atari65xe.com/2019/03/04/atari-graphics-3/
https://www.atariarchives.org/agagd/chapter1.php
https://www.atariarchives.org/c2bag/page020.php
http://antic-things.blogspot.com/