Starwars Electronic Battle Command Pinout
                   -----------------------------------------

10302012 
K.Horton
----


This game is kinda interesting.  The patent for it (number 4270755 for those of
you playing at home) has a schematic and a complete hex dump of the TMS1100's
ROM data.  This was highly useful for figuring out when I had properly dumped
a chip.  The data in the patent seems to be from an earlier revision of the
code, however.  Much of the data is the same, but some of it did change. 
There's enough data to confirm bank ordering and chapter ordering and byte 
ordering though.  



The display on it is composed of 18 LEDs and 2 7 segment displays.


  1     2     3     4    ALERT
A *     *     *     *      *

B *     *     *     *    COMBAT
                           *
C *     *     *     *   
                          88  (7-segs)
D *     *     *     *


The 18 LEDs are arranged in a grid of 4*4 (16) and two single ones to the right
of the 4*4 array.  The two 7 segment displays are little "bubble" displays
and sit under the 'COMBAT' LED.


Electrically, it's a 5*8 matrix of LEDs.


The 8 outputs map to the 7-seg displays like so:

O0 - E
O1 - F
O2 - G
O3 - 
O4 - A
O5 - B
O6 - C
O7 - D

The left 7-segment is connected to R6, and the right one is connected to R8.

The 4*4 grid is electrically an 8*2 grid:

O0 - B1  D1  COMBAT
O1 - B2  D2  ALERT
O2 - B3  D3
O3 - B4  D4
O4 - A1  C1
O5 - A2  C2
O6 - A3  C3
O7 - A4  C4

     R2  R4   R0

The R2 and R4 outputs drive the commons for 8 of the LEDs for the 4*4 grids each
while R0 drives the 2 single LEDs, and R6 and R8 drive the 7-seggers.


The patent shows a schematic of the display and it exactly matches what I
fluked out with the multimeter.




Thanks to the patent, here's the key layout:

       +----+  +----+  +----+  +----+
R3 o---| BG |--| IG |--| AG |--| #  |
       +----+  +----+  +----+  +----+
          |       |       |       |
       +----+     |       |    +----+
R5 o---| ST |-----+-------+----| ET |
       +----+     |       |    +----+
          |       |       |       |
       +----+  +----+  +----+  +----+
R6 o---| EM |--| MV |--| FI |--| BS |
       +----+  +----+  +----+  +----+
          |       |       |       |
       +----+  +----+  +----+  +----+
R7 o---| L  |--| U  |--| D  |--| R  |
       +----+  +----+  +----+  +----+
          |       |       |       |
       +----+  +----+     |    +----+
R9 o---| MS |--| ES |-----+----| SU |
       +----+  +----+     |    +----+
          |       |       |       |
          o       o       o       o
         K1      K2      K4      K8



BG, IG, AG:  beginner, intermediate, advanced game
#: # of players
ST, ET:  start/end turn
EM = evasive manuvers, MV = move, FI = fire, BS = battlestations
LUDR = movement direction (left, up, down, right)
MS = magnascan, ES = enemy scan, SU = shields up

I checked the keypad layout and it matches the patent exactly.


Finally there is sound.  It's a piezo feeper glued into a plastic housing that
makes it resonate and sound louder.  It's connected to R9.  As before with the
other games, the code has to manually bit-bang R9 to make noises.  So they
use pin toggling and software delays to make noises and tones.  The patent
shows this circuit using R9 and R10 to make the sounds, but the production
game only uses R9 without any of the mickeymouse shown.

R10 goes to a pad which is not connected to anything, so maybe it outputs
some tones/audio too?  I suspect not, though, hence all the code changes
in the ROM data.