The MOS 6567/6569 video controller (VIC-II)
and its application in the Commodore 64
Contents
3. Description of the VIC
3.7. Text/bitmap display
3.7.3. Graphics modes
3.7.3.1. Standard text mode (ECM/BMM/MCM=0/0/0)
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In this mode (as in all text modes), the VIC reads 8 bit character pointers from the video matrix that specify the address of the dot matrix of the character in the character generator. A character set of 256 characters is available, each consisting of 8×8 pixels which are stored in 8 successive bytes in the character generator. Video matrix and character generator can be moved in memory with the bits VM10-VM13 and CB11-CB13 of register $d018.

In standard text mode, every bit in the character generator directly corresponds to one pixel on the screen. The foreground color is given by the color nybble from the video matrix for each character, the background color is set globally with register $d021.

c-access

Addresses
13 12 11 10 9 8 7 6 5 4 3 2 1 0
VM13 VM12 VM11 VM10 VC9 VC8 VC7 VC6 VC5 VC4 VC3 VC2 VC1 VC0

Data
11 10 9 8 7 6 5 4 3 2 1 0
Color of "1" pixels D7 D6 D5 D4 D3 D2 D1 D0

g-access

Addresses
13 12 11 10 9 8 7 6 5 4 3 2 1 0
CB13 CB12 CB11 D7 D6 D5 D4 D3 D2 D1 D0 RC2 RC1 RC0

Data
7 6 5 4 3 2 1 0
8 pixels (1 bit/pixel)

"0": Background color 0 ($d021)
"1": Color from bits 8-11 of c-data