Star Tech Journal

11
STARHECH JOURNAL/AUGUST 1982
POWER SUPPLY -The game power supply was designed to be
used for all games of the MCR-11 series and vector scan systems. Its
operation is similar to that of most other multivoltage game power
supplies. There are regulator circuits to provide +5 volts at 7.5 amps as
well as +12 volts at 4 amps. Bothof these circuits are extremely similar,
employing LM 305 regulators in a standard fold-back current limiting
circuit design; this regulator circuit is designed to compensate for
variations in either the line voltage or the load. In addition to the
regulated voltages, the power supply also generates an unregulated
auxiliary voltage. This voltage is developed by a full wave bridge
rectifier located on the power supply. This unregulated+ 12 volts is used
to drive the (if required) "controlled" lamps on the coin door. Take note
that this same unregulated + 12-volt source is filtered by a 4 700 MFD
capacitor and used to drive the audio amps.
The final voltage emanating from this power supply is the 3.6vdc for
the NICAD battery. This voltage, as always, supplies the bookkeeping
RAM when power is off.
In addition to the already mentioned voltages, the power supply
provides the system reset signal. This is especially vital since this signal
is necessary to clear the computer and make it start from the beginning
when power is applied. The five principle elements of the reset circuit
include the opto-isolator, pump charger, one shot, logic "OR" and the
output amplifier.
VOLTAGE ADJUSTMENTS -Both the +5 and +12 volts can
be adjusted with potentiometers on the power supply (VRl O 1 - + 5vdc,
VR102 - + l 2vdc ). As always, these pots should only be turned while
measuring the voltages on the game logic boards.
Location
Power Supply
Filter Assy.
Filter Assy.
Transformer Assy.
Transformer Assy.
Transformer Assy.
Transformer Assy.
Transformer Assy.
FUSES
Value
¾ amp
6 amp
IO amp
3 amp S.B.
2 amp S.B.
2 amp S.B.
1.5 ampS.B.
2 amp S.B.
SELF TEST/OPTIONS
Like most domestic video games, "Tron" possesses an extremely
thorough self-test feature. The test switch is located just inside the
cabinet on the right side of the coin door frame. The easiest method of
entering self test is to slide the switch to the on position and then activate
the slam switch on the bottom of the coin door. There are eight major
categories which can be selected one at a time by moving the cursor
(video pointer) with the control stick and depressing the fire button.
Checks
ROMs and RAMs
26 game sounds
Coin door and control panel switches
Coin totals and misc. game information
Options
Sound gen. (A Y-3-8910) output channels
Bookkeeping and option reset
Monitor alignment
Test
• 1. Self Diagnostics
2. Sounds
3. Player Input
4. Bookkeeping
5. Machine Setup
6. Channel Test
7. Preset
8. Grid Display
*Located in the game manual is a section regarding certain diagnostic
tests which can be entered into by setting switches on dipswitch #3 at
location D14. On a goud board, the sound 1/0 diagnostic test will read
"sound interface error". This is a normal condition and should be
ignored. The usefulness and validity of the other tests in this section are
questionable for anything other than bench repairs. This entire section
should probably be ignored. The normal game self-test is sufficient.
In addition to the diagnostic steps, please take note there are also
bookkeeping ( # 4) and bookkeeping reset ( #7) categories included in the
self-test-mode-"menu". (See table.)
Circuit
+5vdc (preamp)
Preregulated + l 5vdc
Preregulated +8vdc
Line in AC
Service outlet
Isolated line (monitor)
Fluorescent lights
Unregulated+ 12
OPTIONS - Options can be set during the "machine setup" (5)
section of self test and by dipswitch # 1 located at position B3 on the
super sound 1/0 board. Only a limited number of options, including one
for freezing video operation (for board repairs), are adjustable using the
dipswitch. The majority of options are set during the "machine setup"
section of self test.
There is a red service (credit) switch locatedjust below the self-test
switch to add credits without affecting coin totals.
SYSTEM POWER
1
- - - - - - - - 1 1 Svac Isolated
Monitor
6
+3.6vdc
Service
Outlet
On/Off
Switch
------12vac - - -- - - ~
l
Line
Voltage
Line
Filter
surur
C U
&
Angle
Encoder
Boards
+12vdc
Power
Supply
H
T
Interlock
Switches (2)
+5vdc
+12vdc
(Unreg .)
Filtered
-
+12vdc-
(Unreg.)
15vac
+15vdc
~
/
Filter
Assy.
*
+Bvdc
Bvac
Fluorescent Lights
Notes:
1. On/off switch located on top of cabinet toward the
back.
2. Two interlock switches; 1 located on each back door.
3. *There are three fluorescent tubes, each with its own
line filter.
4. /j. 3.6vdc - battery voltage.
'-
,/
Dual
Amp
Board
Coin
Door
Lamps