PCB Layout:
+----------------------------------------------------------------------------------------------------------------------------+
|      J       I       H         G            F         E         D           C          B              A           push     |
|                                                                        +----------+                               button   |
|   +-----+ +-----+ +-------+ +-----+                +-----+             |RAM 6116  | +--------------+ +-----+            +--+
|14 |  U  | |  U  | |   F   | |  T  |                |  M  |             |          | |     [8]      | |  R  |            |
|   +-----+ +-----+ +-------+ +-----+                +-----+             |(missing) | |   M27C256B   | +-----+            |
|                                                                        +----------+ |              |                    +--+
|   +-----+           +-----+ +-----+      +-----+   +-------+ +-----+   +-------+    +--------------+ +-----+             --|
|13 |  H  |           |  V  | |  T  |      |  H  |   |   F   | |  S  |   |   A   |                     |  P  |             --|
|   +-----+           +-----+ +-----+      +-----+   +-------+ +-----+   +-------+                     +-----+             --|
|                +----------+                                                                                              --|
|                |TEMIC     | +-----+                +-----+   +-----+   +-------+                                         --|
|12              |HM3-6116-5| |  O  |                |  B  |   |  S  |   |   A   |                                         --|
|                |          | +-----+                +-----+   +-----+   +-------+                                         --|
|                +----------+                                                                                              --|
|                +----------+                                            +------------------+                              --|
|                |TEMIC     | +-----+                +-----+   +-----+   |     Z80 CPU      |                              --|
|11              |HM3-6116-5| |  O  |                |  B  |   |  L  |   |    (missing)     |                              --|
|                |          | +-----+                +-----+   +-----+   |                  |                              --|
|                +----------+                                            +------------------+                              --|
|   +-----+  +--------------+ +-----+      +-----+   +-----+   +-----+   +------------------+                              --|
|10 |  J  |  |     [7]      | |  O  |      |  W  |   |  B  |   |  X  |   |    INTEL         |                              --|
|   +-----+  |   M27C256B   | +-----+      +-----+   +-----+   +-----+   |    P8255A-5      |                              --|
|            |              |                                            |                  |                              --|
|   +-----+  +--------------+ +-----+      +-----+   +-----+   +-----+   +------------------+                            36--|
|9  |  J  |  +--------------+ |  O  |      |  E  |   |  C  |   |  L  |                                                 Pinout|
|   +-----+  |     [6]      | +-----+      +-----+   +-----+   +-----+   +------------------+                              --|
|   +-----+  |   M27C256B   | +-------+    +-----+   +-----+ +--------+  |    INTEL         |                              --|
|8  |  J  |  |              | |   I   |    |  E  |   |  D  | |  DIP1  |  |    P8255A-5      |                              --|
|   +-----+  +--------------+ +-------+    +-----+   +-----+ +--------+  |                  |                              --|
|   +-----+  +--------------+ +-------+              +-----+ +--------+  +------------------+ +---+ +-----+                --|
|7  |  G  |  |     [5]      | |   I   |              |  E  | |  DIP2  |  +------------------+ | Q | |  P  |                --|
|   +-----+  |   M27C256B   | +-------+              +-----+ +--------+  |    INTEL         | +---+ +-----+                --|
|            |              |                                            |    P8255A-5      |                              --|
|    XTAL    +--------------+ +-------+              +-----+             |                  |       +-----+                --|
|6  .----.   +--------------+ |   I   |              |  L  |             +------------------+       |  P  |                --|
|            |     [4]      | +-------+              +-----+             +------------------+       +-----+                --|
|            |   AM27C64    |                                            |     Winbond      |                              --|
|   +-----+  |              | +-------+    +-----+   +-----+ +--------+  |     WF19054      |                              --|
|5  |  O  |  +--------------+ |   I   |    |  K  |   |  B  | |  DIP3  |  |                  |                              --|
|   +-----+  +--------------+ +-------+    +-----+   +-----+ +--------+  +------------------+                              --|
|            |     [3]      | +----------+                                                                                 --|
|   +-----+  |   AM27C64    | |TEMIC     | +-----+   +-----+ +---------+  +------+ +------+                                --|
|4  |  J  |  |              | |HM3-6116-5| |  K  |   |  B  | |    I    |  |    V | |   X  |                                --|
|   +-----+  +--------------+ +----------+ +-----+   +-----+ +---------+  +------+ +------+                               +--+
|   +-----+  +--------------+ +----------+ +-----+   +-----+ +-------+    +------+ +------+                               |
|3  |  J  |  |     [2]      | |TEMIC     | |  T  |   |  E  | |   H   |    |    V | |   X  |                               |
|   +-----+  |   AM27C64    | |HM3-6116-5| +-----+   +-----+ +-------+    +------+ +------+                               +--+
|            |              | +----------+                                                                                   |
|   +-----+  +--------------+ +----------+ +-----+   +-----+  +------+    +------+     trimmer        trimmer                |
|2  |  J  |  +--------------+ |TEMIC     | |  O  |   |  M  |  |   Y  |    |   Z  |     VAL 10K        VOL 10K                |
|   +-----+  |     [1]      | |HM3-6116-5| +-----+   +-----+  +------+    +------+                                           |
|   +-----+  |   AM27C64    | +----------+ +-----+   +-----+  +------+                                            +-------+  |
|1  |  J  |  |              | +----------+ |  O  |   |  N  |  |   W  |                                            |NEC    |  |
|   +-----+  +--------------+ |TEMIC     | +-----+   +-----+  +------+                                  A         |C1181H3|  |
|                             |HM3-6116-5|                                           +-----+    10 Pins   +-----+ +-------+  |
|      J       I       H      +----------+    F         E         D           C     B|     ||||||||||||||||     |            |
+------------------------------------------------------------------------------------+     +--------------+     +------------+


DIP1:                     DIP2:                     DIP3:
+-------------------+     +-------------------+     +-------------------+
| ON                |     | ON                |     | ON                |
| +---------------+ |     | +---------------+ |     | +---------------+ |
| |_|_|_|_|#|#|_|_| |     | |#|#|#|_|_|_|_|_| |     | |#|#|#|_|#|#|_|_| |
| |#|#|#| | | |#|#| |     | | | | |#|#|#|#|#| |     | |#|#| |#| | |#|#| |
| +---------------+ |     | +---------------+ |     | +---------------+ |
|  1 2 3 4 5 6 7 8  |     |  1 2 3 4 5 6 7 8  |     |  1 2 3 4 5 6 7 8  |
+-------------------+     +-------------------+     +-------------------+


1x XTAL = 12 Mhz


A = 74LS244
B = 74LS161
C = 74LS10
D = 74LS11
E = 74LS74
F = 74LS273
G = 74LS368
H = 74LS32
I = 74LS245
J = 74166
K = 74LS283
L = 74LS138
M = 74LS04
N = 74LS139
O = 74LS157
P = 74LS04
Q = NE555N
R = 74HC00
S = N82S123AN
T = AM27S21APC
U = 74LS02
V = 74LS174
W = 74LS08
X = 74LS367
Y = 74LS00
Z = SN76489AN