Williams Video Games Hardware Identification and Compatibility

There are so many PCB hardware revisions for the early Williams video games such as Defender, Robotron, Joust etc that often it is not easy to decide which game boards belong to. This page allows you to identify each board, view a high resolution image for comparison with your own boards and download the schematics pertaining to the particular board revision. The schematics will be useful since many game owners find that they have 'mix and match' boardsets that are not covered by any one manual!

Many thanks to Joe Magiera and Phil Murrayfor some of the board images seen here!

Currently this page has information on the following games:

Jump to Defender boards Jump to Stargate boards Jump to Robotron boards Jump to Joust boards Jump to Sinistar boards
Jump to Bubbles boards Jump to Turkey Shoot boards Jump to Joust 2 boards Jump to Mystic Marathon boards Jump to Inferno boards



Jump to:






Board Identification
Jump to:

Defender has two completely different versions of the boards known as early series boards and later series boards. The later series boards were introduced to allow cocktail (or tabletop) games where the screen flips between players and two sets of controls are supported.

Early and later series boards can be mixed with no compatibility problems with the following exceptions:

  • You CANNOT use ANY Defender Board in another Williams (or other) game!
  • You CANNOT use an early series CPU or Interface in a tabletop game as it lacks the circuits to flip the screen.
  • You MUST use red-label game ROMs in a tabletop game.
  • You MUST remove jumper W1 in a later series interface when using in a tabletop game.
  • You MUST remove jumper W2 in a later series interface when using WITHOUT red-label ROMs.

In addition to the two hardware revisions there are three software revisions, namely Red, Green and Blue label ROMs with Red label ROMs being the latest revision. Red and Green label ROM sets have 11 EPROMs, it is normal for ROM number 5 to be missing. Blue label ROM sets have 10 EPROMs, it is normal for EPROMs 4 and 5 to be missing.

For more information on Defender refer to the Defender manuals page.



D8356 (Early Series) Defender CPU Board
View a high resolution image of the D8356 (early series) Defender CPU Board
Identifiable by batteries at top right of board, a single
decoder PROM and 5770-09471-?? (??=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (120Kb)
Schematics (not online)

Note: This CPU board can only be used in UPRIGHT Defender games.
The two wires on this board are a factory fitted modification.
R8570 (Later Series) Defender CPU Board
View a high resolution image of the R8570 (later series) Defender CPU Board
Identifiable by batteries at the bottom right of board, two
decoder PROMs and 5770-09616-?? (??=Revision) etched above battery holder

Links for this PCB:
High Resolution Image (129Kb)
Schematics (not online)

Note: This CPU board can be used in Upright and Cocktail Defender games.
For cocktail games decoder PROMs 2 and 3 must be fitted.



D8520 (Early Series)
ROM Board

View a high resolution image of the (early series) Defender ROM board
Identifiable by 5771-09472-??
(??=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (75Kb)
Schematics (not online)

Note: This ROM board is capable of on
running all Defender games. Requires
different jumpers for blue-label ROMs
D8121 (Early Series) Sound Board
View a high resolution image of the D8121 (early series) sound board
Identifiable by IC-2001-137-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (62Kb)
Schematics (not online)

Note: This sound board is capable of
running Defender, Stargate
and some pinball games only.
C8353 (Early Series)
Interface Board

View a high resolution image of the C8353 (early series) Defender interface board
Identifiable by 5772-09473-??
(??=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (53Kb)
Schematics (not online)

Note: This interface board
is capable of on running
UPRIGHT games only.



D8572 (Later Series)
ROM Board

View a high resolution image of the (later series) Defender ROM board
Identifiable by 5771-09615-??
(??=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (72Kb)
Schematics (not online)

Note: This ROM board is capable of on
running all Defender games. Requires
different jumpers for blue-label ROMs

D8224 (Later Series) Sound Board
View a high resolution image of the D8224(later series) sound board
Identifiable by 1B-2001-146-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (102Kb)
Schematics (not online)
Jumpering guide

Note: This sound board is capable of running
Defender, Stargate, Robotron, Joust, Splat!,
Sinistar, Blaster and various Pinballs.
C8573 (Later Series)
Interface Board

View a high resolution image of the C8573 (later series) Defender interface board
Identifiable by 5772-09614-??
(??=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (48Kb)
Schematics (not online)

Note: This interface board
is capable of on running
all Defender games.






Board Identification
Jump to:

Stargate runs on similar hardware to Robotron and Joust, but the ROM board lacks the two Special Chip 1s (SC1) required for these games run.

Each Stargate boardset consists of four boards, the CPU, ROM, sound and interface (or widget) boards.

For more information on Stargate refer to the Stargate manuals page.

R8948 (Revision -) CPU Board
View the R8948/R8731 CPU board page showing details of all revisions
There are 4 different revisions of the R8948/R8731 CPU board
Click the photo above or HERE to see detailed information
including hi-res images and schematics for each revision.


Note: The R8948 CPU board is capable of running Stargate
and after BS.BA modification Robotron, Joust, Splat! and Sinistar.



D8224 Sound Board
View a high resolution image of the D8224 sound board
Identifiable by IC-2001-146-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (102Kb)
Schematics (not online)
Jumpering guide

Note: This sound board is capable of running
Defender, Stargate, Robotron, Joust, Splat!,
Sinistar, Blaster and various Pinballs.
D8730 ROM Board
View a high resolution image of the D8730 ROM board
Identifiable by 5771-09657-00
etched on the PCB

Links for this PCB:
High Resolution Image (120Kb)
Schematics (not online)

Note: This ROM board is capable
of running Stargate only


C8783 Interface Board
View a high resolution image of the C8783 interface board
Identifiable by 5772-09680-00
etched on the PCB

Links for this PCB:
High Resolution Image (62Kb)
Schematics (not online)

Note: This interface board is capable
of running Defender, Stargate,
Robotron, Joust and Splat!.






Board Identification
Jump to:

Robotron and Joust games run on identical hardware, so both games are covered here. To convert between the two games all you need to do is reprogram the 12x game EPROMs and 1x sound EPROM to the appropriate game. The extremely rare game Splat! also runs on this hardware, however, the Splat! ROM boards had two Special Chip 2s (SC2) fitted instead of the Special Chip 1s (SC1) found on Robotron and Joust so it is not plug and play ... unless you have access to the ROM version that has been modified for Special Chip 1 use. Stargate ROMs will run on a Robotron/Joust boardset without modification, and will also run perfectly if the two SC1s have been removed.

Each Robotron/Joust boardset consists of four boards, the CPU, ROM, sound and interface (or widget) boards.

For more information on Robotron refer to the Robotron manuals page.

For more information on Joust refer to the Joust manuals page

R8731 CPU Board
View the R8731 CPU board page showing details of all revisions
There are 4 different revisions of the R8948/R8731 CPU board
Click the photo above or HERE to see detailed information
including hi-res images and schematics for each revision.


Note: The R8948 CPU board is capable of running
Stargate, Robotron, Joust, Splat! and Sinistar.



D8224 Sound Board
View a high resolution image of the D8224 sound board
Identifiable by IC-2001-146-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (102kB)
Schematics (not online)
Jumpering guide

Note: This sound board is capable of running
Defender, Stargate, Robotron, Joust, Splat!,
Sinistar, Blaster and various Pinballs.
D9144 ROM Board
View a high resolution image of the D9144 ROM board
Identifiable by 5771-09840-00
etched on the PCB

Links for this PCB:
High Resolution Image (118kB)
Schematics (not online)

Note: This ROM board is capable of running
Robotron, Joust, Stargate and Splat!
(Use SC2 with Splat! No SC1
or SC2 required for Stargate)
C8783 Interface Board
View a high resolution image of the C8783 interface board
Identifiable by 5772-09680-00
etched on the PCB

Links for this PCB:
High Resolution Image (62kB)
Schematics (not online)

Note: This interface board is capable
of running Defender, Stargate,
Robotron, Joust and Splat!.






Board Identification
Jump to:

Each Sinistar boardset consists of five boards, the CPU, ROM, sound, speech and interface (or widget) boards. In addition to the normal CPU, ROM, interface and sound boards a speech board is added. Cockpit games also have a second sound board making it a 6 board set.

For more information on Sinistar refer to the Sinistar manuals page.

R8731 CPU Board
View the R8731 CPU board page showing details of all revisions
There are 4 different revisions of the R8948/R8731 CPU board
Click the photo above or HERE to see detailed information
including hi-res images and schematics for each revision.


Note: The R8948 CPU board is capable of running
Stargate, Robotron, Joust, Splat! and Sinistar.
D9176 ROM Board
View a high resolution image of the D9176 ROM board
Identifiable by 5771-09859-00
etched on the PCB

Links for this PCB:
High Resolution Image (127kB)
Schematics (not online)

Note: This ROM board is
capable of running Sinistar only.



C9191 Interface Board
View a high resolution image of the C9191 interface board
Identifiable by 5772-09869-00
etched on the PCB

Links for this PCB:
High Resolution Image (95kB)
Schematics (not online)

Note: This interface board is capable of
running Sinistar and Blaster only.


D8224 Sound Board
View a high resolution image of the D8224 sound board
Identifiable by IC-2001-146-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (102kB)
Schematics (not online)
Jumpering guide

Note: This sound board is capable of running
Defender, Stargate, Robotron, Joust, Splat!,
Sinistar, Blaster and various Pinballs.
C8228
Speech Board

View a high resolution image of the C8228 speech board
Identifiable by IC-2001-147-3
etched on the PCB

Links for this PCB:
High Resolution Image (47kB)
Schematics (not online)

Note: This speech board is
capable of running Sinistar and
various Williams Pinballs only.






Board Identification
Jump to:

Bubbles runs on *almost* identical hardware to Robotron and Joust, except that the CMOS RAM is 8 bits wide instead of 4 bits wide. To stop board problems Williams made the CPU to ROM board cable a different pinout to the other games so a Bubbles CPU and ROM board will only work together and not mixed with other boards. You can however ROM swap a working Bubbles boardset to Robotron, Joust, Stargate or Splat! (with modified ROMs) with no problems as the software just ignores the extra 4 bits of CMOS RAM.

R9663 CPU Board
View a high resolution image of the R9663 CPU Board
Identifiable by inductors next to the PCB power connector
and 5770-10179-00 Rev. etched above battery holder and the
extra CMOS RAM chip next to the ROM board connector.

Links for this PCB:
High Resolution Image (137kB)
Schematics (not online)

Note: This CPU is capable of running Bubbles, Stargate,
Robotron, Joust, and Splat! when used with a Bubbles ROM board.




D8224 Sound Board
View a high resolution image of the D8224 sound board
Identifiable by IC-2001-146-?
(?=Revision) etched on the PCB

Links for this PCB:
High Resolution Image (102kB)
Schematics (not online)
Jumpering guide

Note: This sound board is capable of running
Defender, Stargate, Robotron, Joust, Splat!,
Sinistar, Blaster and various Pinballs.
D9144-3012 ROM Board
View a high resolution image of the D9144-3012 ROM board
Identifiable by 5771-10177-00
etched on the PCB

Links for this PCB:
High Resolution Image (82kB)
Schematics (not online)

Note: This ROM board is capable of running
Bubbles, Robotron, Joust, Stargate and Splat!
but only when used with a Bubbles CPU board.

C8783 Interface Board
View a high resolution image of the C8783 interface board
Identifiable by 5772-09680-00
etched on the PCB

Links for this PCB:
High Resolution Image (62kB)
Schematics (not online)

Note: This interface board is capable
of running Defender, Stargate,
Robotron, Joust and Splat!.






Board Identification
Jump to:

Turkey Shoot runs on similar hardware to Mystic Marathon, Joust 2 and Inferno but has an extra gun interface board. Boards *may* be compatible (i.e. interchangeable) between these games with little or modification but I cannot guarantee this.

CPU Board
View a high resolution image of the CPU Board
Identifiable by 5780-10333-00 etched on the PCB

Links for this PCB:
High Resolution Image (135kB)
ROM Board
View a high resolution image of the ROM Board
Identifiable by 5770-10694-00 etched on the PCB

Links for this PCB:
High Resolution Image (123kB)


D10413 Gun Interface Board
View a high resolution image of the D10413 gun interface board
Identifiable by 5772-10697-00
etched on the PCB

Links for this PCB:
High Resolution Image (73kB)





Board Identification
Jump to:

Joust 2 runs on similar hardware to Mystic Marathon, Turkey Shoot and Inferno but has an extra sound board. Boards *may* be compatible (i.e. interchangeable) between these games with little or modification but I cannot guarantee this.

D10556 CPU Board
View a high resolution image of the D10556 CPU Board
Identifiable by 5780-10759-00 etched on the PCB

Links for this PCB:
High Resolution Image (146kB)
D9870 ROM Board
View a high resolution image of the D9870 ROM Board
Identifiable by 5770-10350-00 etched on the PCB

Links for this PCB:
High Resolution Image (132kB)


D11298 Sound Board
View a high resolution image of the D11298 sound board
Identifiable by 5766-12057-00
etched on the PCB

Links for this PCB:
High Resolution Image (101kB)





Board Identification
Jump to:

Mystic Marathon runs on similar hardware to Turkey Shoot, Joust 2 and Inferno. Boards *may* be compatible (i.e. interchangeable) between these games with little or modification but I cannot guarantee this.

CPU Board
View a high resolution image of the CPU Board
Identifiable by 5780-09660-00 etched on the PCB

Links for this PCB:
High Resolution Image (142kB)
ROM Board
View a high resolution image of the ROM Board
Identifiable by 5770-09959-00 etched on the PCB

Links for this PCB:
High Resolution Image (119kB)





Board Identification
Jump to:

Inferno runs on similar hardware to Turkey Shoot, Joust 2 and Mystic Marathon. Boards *may* be compatible (i.e. interchangeable) between these games with little or modification but I cannot guarantee this.

CPU Board
View a high resolution image of the CPU Board
Identifiable by 5780-10759-00 etched on the PCB

Links for this PCB:
High Resolution Image (121kB)
ROM Board
View a high resolution image of the ROM Board
Identifiable by 5770-10330-00 etched on the PCB

Links for this PCB:
High Resolution Image (106kB)







Disclaimer: Although I have done my best to ensure that all information contained on this
page is correct, I can take no responsibility for damage to your game, its boards or yourself!