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
3.7.3.8. Invalid bitmap mode 2 (ECM/BMM/MCM=1/1/1) |
The last invalid mode also creates a black screen but it can also be "scanned" with sprite-graphics collisions. The structure of the graphics is basically as in multicolor bitmap mode, but the bits 9 and 10 of the g-addresses are always zero due to the set ECM bit, with the same results as in the first invalid bitmap mode. As usual, the bit combination "01" is part of the background. c-access
Adresses
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
unused
g-access
Adresses
13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
CB13 | VC9 | VC8 | 0 | 0 | VC5 | VC4 | VC3 | VC2 | VC1 | VC0 | RC2 | RC1 | RC0
Data
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
4 pixels (2 bits/pixel) "00": Black (background) "01": Black (background) "10": Black (foreground) "11": Black (foreground)