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STAR*TECH JOURNAL/JANUARY 1983
A Regular Monthly Feature Technically Outlining a Newly Released Game
WILLIAMS' ''JOUST''
By Joe Connor, Active Amusement Co., Philadelphia, PA
One of the hottest new pieces now on the street is Williams'
latest video game, "Joust". This one or two player game is the
fourth game employing a video system which was totally
designed and engineered by Williams Electronics. This
system was somewhat revolutionary, first appearing in
"Defender". It demonstrated that a normal color raster scan
monitor ( who needs X-Y?) in conjunction with a sophisticated
board system ( state-of-the-art display section) could produce
a game of extraordinary color graphics. The outstanding
visual and audio effects of "Defender" certainly contributed
as much to its success as the game play itself.
"Joust" carries on the tradition of "Defender" and the
other two games featuring this electronic system (" Stargate"
and" Robotron") with its outstanding graphics and fast-paced
action requiring keen eye-to-hand coordination. Game play
consists of a gladiator mounted on a "fanciful bird of prey"
whose wings (player controlled) can carry it from perch to
perch while dueling with a flock of "Buzzard Riders". The
player must joust with these enemies ( and/or the other player
in a two player game) avoiding the bubbling lava and a hand of
flame which reaches up from the lower comers. Scoring is
accomplished by toppling your opponents (in every joust the
highest lance wins) and by picking up the eggs the "Buzzard
Riders" lay before they hatch into even more determined and
antagonistic foes. The usual array of options affecting bonus
mounts and game difficulty is also available, so game play
may be "customized" for each individual location.
SYSTEM COMPATIBILITY
As mentioned earlier, "Joust" is the fourth game employing
basically the same multi-board electronic package. Since its
inception ("Defender" 1981), this system has undergone a
slight metamorphosis. Based on field reports (complaints), Williams made slight
changes for improved servicing, operating, and overall reliability. Essentially
"Defender'' was the prototype of the system. Some changes were made to
"Stargate" halfway through the production run - these changes (improvements)
were then completely incprporated into "Robotron". The electronics in "Robotron"
is essentially the same as that found in" Joust". Naturally, the game PRO Ms on the
ROM board and sound board vary for each of the four different games. The
following tables of compatibility were constructed using the instruction manuals for
each particular game.
CPU BOARD
Decoder ROMs
Rev.
Bd.No.
Game
(1 and2)or(2and3)
R8570
Defender
(4 and5) or(4 and6)
B
Stargate
R8948
C or modified B
4 and 6
R8731
Robotron
4 and 6
D
R8731
Joust
NOTES
1) "Defender'' CPU boards are non-interchangeable with other games.
2) "Stargate" logic boards can be modified and made compatible for use in "Robotron" and
"Joust''. In "Stargate", the signal BS.BA is routed via IJ4 pin 32 to the ROM board. In
"Robotron" and "Joust'', this same signal is inverted (BS.BA) before entering the ROM
board. The signal BS.BA is not used on the "Stargate" ROM board, hence a modified Rev B
or R8731 board is good for use in any of three games(without being demodified to put back
in a "Stargate"). For directions and an illustration on this modification see S*TJ (Vol. 4, No.
8).
3) "Defender'' boards can most easily be identified by the (22 pin) 5101 CMOS RAM in the
upper left hand corner of the board. ("Stargate", "Robotron", and "Joust" games use a (18-
pin) 6514 RAM in this location).
4) Most "Stargate" boards can be easily identified by the small piggy-back board in location
6D (factory installed CMOS RAM modification).
5) R 8731 Boards -
__
Rev B Board needs BS.BA modification.
Rev C Have never seen one but I would assume the BS.BA mod is in copper.
Rev D BS.BA mod in copper and RF chokes added to voltage inputs (FCC regulations).
ROM BOARD
Bd.No. ROM Size ROM Label Colors
Game
2KX8
Red or Green
Defender D8572
4KX8
Yellow
Stargate
D8730
4KX8
Red, Yellow, or Blue
Robotron D9144
4KX8
•Yellow,Red,orGreen
D9144
Joust
NOTES
1) "Defender'' PROM board is unique and non-interchangeable with
other games.
2) "Stargate" PROM board is unique and non-interchangeable with
, other games.
3) "Robotron" and "Joust'' are the same and interchangeable.
4) 4KX8 PRO Ms may be either 2532 or 2732 EPROMs. Strap -
W1 and W3 for 2732; W2 nd W4 for 2532 EPROMs.
5) There are probably additional colored PROMs for some games.
These colors were identified using the game manual listings. Colors
indicate different program revisions (most manufacturers usually
just indicate the revisions with a dash number (01, 02, 03, etc.).
Williams uses color coding instead.
*Current "Joust" games use green label RO Ms. Earlier games have
either yellow or red label ROMs which are interchangeable, and
may be mixed in the same game. Green label ROMs, however,
CANNOT be mixed with red or yellow label ROMs.
POWER SUPPLY/TRANSFORMER
Game
Number
Defender
D8359
Stargate
D8359, D8784
Robotron
D8784
Joust
D8784
NOTES
1) "Stargates" were originally manufactured using the D8359 power supply; most,
however, came with the new style D8784 type with a se_parate heatsink assembly.
2) "Stargates" with the older type power supply had a small interface board on the output
connector. This board had two SC R type crowbar circuits for protection on it
3) The new power supply incorporates these +5vdc and +12vdc over-voltage protection
circuits directly on the power supply.
4) The old power supply used a transformer (part no. 5610-09535) with 8 primary and 9
secondary terminals. The new power supply uses a transformer (part no. 5610-09658) with
8 primary and 12 secondary terminals. For more detailed description of these two power
supplies and their compatibility with the two different transformers, see the Williams
Service Bulletin in S*TJ (Volume 4, No. 8).
Game
Defender
Stargate
Robotron
Joust
SOUND BOARD
Number
Sound ROM
D8121, D8824
1
D8824
2
D8824 - 3005
3
D8824 - 3005
4
ROM Size
2KX8
2KX8
4KX8 (2532)
4KX8 (2532)
NOTES
11 Early "Defender'' used the old style (D8121) ("flash"-type) pinball sound board. Most
used the new style (D8824) pinball ("Black Knight'') sound board.
2) Sound boards of the same number should be interchangeable. Jumper changes required
for different size PROMs. W2 and W5 for 16K EPROMs, W3 and W5 for 32K EPROMs.
3) For complete jumper combinations, see either a "Defender'' or "Stargate" game manual.
INTERFACE BOARD
Number
Game
Defender
C8573
C8783
Stargate
Robotron
C8783
Joust
C8783