MOS Technology 8568
This information was adapted from the "Commodore 128 Programmer's Reference Guide" # In Commodore 128 terminology, the VIC-II display was called the 40 column display, and the VDC, 80 column, due to the number of columns of fixed-pitch text that could be natively displayed. # Commodore service manual 314001-08 (1987). # The 8563/8568 hardware is always visible on the address and data buses regardless of which mode in which the C-128 is operating. Hence it is possible to generate an 80 column display while running in C-64 compatibility mode. There is, of course, no C-64 operating system support.
Notes
In the Commodore 128 service manual, this part was referred to as the "80 column CRT controller." Commodore 128 used the 8563 video controller to generate the 80 column display.