Mattel Dallas

Chip labeled 
/B129
COP444L-HYN/N

23 buttons
8-digit 7-segment LED display
Piezo buzzer


COP444 pinout
1  GND    9v Batt negative
2  CKO    N/C
3  CKI    101 cap to ground, 57K resistor to +9V
4  /Reset resistor to +9V
5  L7     7-segment LED decimal point segment
6  L6     7-segment LED segment G
7  L5     7-segment LED segment F
8  L4     7-segment LED segment E
9  IN1    buttons column
10 IN2    buttons column
11 Vcc    9v battery positive via switch
12 L3     7-segment LED segment D
13 L2     7-segment LED segment C
14 L1     7-segment LED segment B
15 L0     7-segment LED segment A
16 SI     N/C
17 SO     piezo
18 SK     N/C
19 IN0    buttons column
20 IN3    buttons column
21 G0     digit 1 (right) / buttons row
22 G1     digit 2 / buttons row
23 G2     digit 3 / buttons row
24 G3     digit 4 / buttons row
25 D3     digit 8 (left)
26 D2     digit 7
27 D1     digit 6 / buttons row
28 D0     digit 5 / buttons row


button matrix
     IN0    IN1    IN2    IN3
D1    NO    YES     S      N 
D0    W     ---    NEXT    E 
G3    7      8      9    STATUS
G2    4      5      6    ASSETS
G1    1      2      3    START
G0  CLEAR    0     MOVE  ENTER