(Author: Zonn Moore, 3/16/00 Rev 1.1)
The following describes the cuts, additions and jumpers needed to convert the Star Castle sound board to a War of the Worlds sound board.
A Star Castle "Operation and Maintenance Manual" can be useful in the following description, but shouldn't be necessary.
You will need a single 1k 5% 1/4 watt resistor (Brown, Black, Red, Gold).
Start by placing the Star Castle sound board so the 16 pin connector (J2) is at the top of the board. A little to the right of J2 will be the power connector (J1). Up, Down, Left, Right, Above, and Below all refer to the board in this position..
Let's locate some I.C.'s for those who are "Operation and Maintenance Manual" impaired...
Just to the left of J2 is a 14 pin I.C., a 7414. This is IC1 and will be referred as such from now on. To the left of IC1 is another 14 pin I.C. a 74LS164, this is IC2. To the left of IC2 is a 20 pin I.C. a 74LS377, this is IC3.
Just below IC3 is a 14 pin I.C. a 74LS393, this is IC13. To the right of IC13 is a 16 pin I.C. a 74LS163, this is IC10. To the right of IC10 is another 74LS163, this is IC11. To the right of IC11 is a 14 pin I.C. a 7406, is IC6. And if you've followed me this far you should see ten resistors and a diode just to the right of IC6. IC28 is a 74LS107 and is located between IC13 and IC10, only a couple blocks below. It sits in the middle of some empty circuit board with only three traces leading away from it.
Now to locate some resistors:
Just to the left of IC3 (74LS377), at about the midpoint of IC3, starts a column of resistors. Counting down from the top of the column, the 12th resistor is R75 this is a 2.7k 5% (Red, Violet, Red, Gold) resistor.
The 18th resistor down (don't count the big capacitor) is R100 which is another 2.7k 5% (Red, Violet, Red, Gold) resistor. The 24th resistor down is R86, yet another 2.7K resistor.
If you don't have a manual, you might want to draw the positions of the above IC's and resistors on some scratch paper and label them.
With the current position of the board, all pins 1 of the IC's are at the upper left hand corner of the IC's. IC pin numbers are counted in a U shaped pattern, down the left side, across the bottom, then up the right side.
Lets start with the cuts:
( ) Follow the trace leading from pin 5 of IC3 down. When you reach the end of this trace, just to the right will be a small 3/8" trace running in parallel. Cut the small 3/8" trace. Do NOT cut the trace leading from pin 5 of IC3, this lead was only mentioned as a reference.
( ) Cut the traces coming from the pins 2 and 5 of IC3. These two traces run in parallel, cut them near IC3.
( ) Directly below IC2 and IC1 are three horizontal traces running in parallel with each other (They connect to nothing on top of the board). Cut all three of these traces.
Flip over the board and make the following two cuts (be careful when counting IC pins, they appear as a mirror image when viewed from the bottom).
( ) Cut the trace leading from pin 9 of IC3 to R100.
( ) Cut the trace leading from IC3 pin 12, directly at pin 12.
Flip the board back over, it's time to add the 1k resistor.
( ) Below IC28 (74LS107) is a single 1.25" straight trace, it connects to nothing on top of the board, remember this trace. Along the bottom of the board, above the very bottom row of ICs run four thick traces. Count down to the 3rd thick trace from the top (+5v) and connect a 1k 5% (Brown, Black, Red, Gold) resistor from this trace to the previously described trace that runs below IC28.
Now using some light gauge wire-wrap wire, add the following jumpers:
( ) Connect pin 2 of IC3 (74LS377) to pin 1 of IC6 (7406).
( ) Connect pin 9 of IC3 to the right side of resistor R86.
( ) Connect pin 12 of IC3 to the right side of resistor R75.
( ) Connect pin 16 of IC3 to pin 3 of IC6.
( ) Connect pin 19 of IC3 to the right side of resistor R100.
( ) Connect pin 4 of IC6 to the top side of the 1k resistor just installed.
( ) Locate the three, previously cut, traces that run directly below IC1 and IC2. Short together all three of these traces on the right side of your cut, now connect these three shorted traces to pin 6 of IC3.
As far as the sound board conversion, that's it!
As far as the ROM images, the original Star Castle ROMs are 2k (2716s). The War of the Worlds ROMs are 4k (2732s). They plug into a board that has the Armor Attack / Solar Quest patch on the back of the CPU board. (I'll document that after the holidays.)
The War of the Worlds control panel is identical to Star Castle's, and works as is.
Have fun!
-Zonn