** The VIC-20 and the VIC-20CR

cartridges/
  Commodore VIC-20 cartridges

drives/
  Disk drives

firmware/
  System firmware

251027l1.gif
251027l2.gif
251027l3.gif
251027r1.gif
251027r2.gif
251027r3.gif
  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.

324001_1.gif
324001_2.gif
324001_3.gif
  VC-20 rev.B (PAL, old design).  Assy number 324001-03.  Bad scanning quality.

vic20-left.tiff
vic20-middle.tiff
vic20-right.tiff
  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.

vic20bus.gif
  A block diagram of the VIC-20 bus signals.

vic20mod.gif
  The VIC-20 RF modulator (PAL).

