Troubleshooting guide

Cinematronics Vector Monitor Repair Guide v.1.0
Page 17 of 53
VARIABLE INTENSITIES
Two Cinematronics games utilized variable intensities – Sundance and Solar Quest. Essentially,
these games are able to reproduce continuous fades (in or out) instead of just Normal and Hi
intensities. Very cool effect. You can play any variable intensity game (i.e., Sundance or Solar
Quest) on a two intensity (Hi/Lo) monitor by changing a jumper on the game CPU board. The
variable intensity game ends up playing with all Hi intensity vectors and is therefore
monochromatic. For instance you can play Solar Quest on an Armor Attack monitor, but you can't
play Armor Attack on the Solar Quest monitor without making a lot of changes to the monitor to
remove the add-on intensity board.
However, for testing purposes you can use a Solar Quest monitor with a CCPU that does not have
the multi-intensity jumper set. Although each time the intensity bit is changed on the CCPU game
board you are using, some random value based on the last vector position will be latched as the Z-
intensity. If this results in intensities of blank, then you won't see much. It shouldn't hurt anything
to try.
Sundance 16-Level Intensity PCB
[??]
Solar Quest 64-Level Intensity PCB
Solar Quest uses a slightly different monitor than all the other games. Most Cinematronics games
have a tri-state (2-bit) intensity, which is off/low/high. In Star Castle, for example, walls that have
not been hit are “high” intensity and walls that have been hit once are “low” intensity. Solar Quest
has a little vertical board mounted on the back of the monitor frame. The ribbon cable from the
logic board goes first to this board and then on to the main monitor board. This board has a bunch
of transistors, which apparently make up a 6-bit DAC for the 64-level intensity. As with the game
boards, they figured they could save money by designing their own circuits instead of using off-
the-shelf ICs; Cinematronics really liked discrete components, which is a good thing since
replacements for 74-series TTL, and plain transistors will be around for a LONG time and make
repair possible.
Intensities for Solar Quest are done by using the same data lines that are used to drive the Y DAC,
to send a 6-bit value to a latched intensity DAC. Color apparently uses the same lines, but 12 bits
are latched into the R G B level DACs.
Solar Quest Intensity PCB connection
If you want to convert your Rev.G monitor into a Solar Quest monitor (and assuming you have a
64-level intensity PCB) you can follow these steps. First, there are components that will need to be
removed: resistors R7, R8, R9, R10 and R22, two transistors (Q1, Q3) and the diode D3. The
schematic for the 64-Level board shows the intensity line connecting to the low side of the
brightness pot.