VIC-20CR rev.D (NTSC, new design). Assy number 251027-01. The PAL model
has a crystal frequency of 4433618 Hz, and there is an extra 56pF capacitor
on the solder side of the board, soldered parallel to R5.
This diagram is scanned from the Commodore VIC-20 Programmer's Reference
guide. It describes an early NTSC motherboard and most probably contains
some errors, like the Commodore 64 schematic from the Commodore 64 PRG
does. Possibly Part No 1001006
