TSI Speech+ talking calculator

Chip labeled 
TMS1007NL
AP7619

die labeled 1007A

23 buttons: 0-9, ., +, -, X, /, =, Sqrt, %, M, C, S, +/-, Spkr
1 switch: Sound On/Off
9 7-segment LEDs
speaker


TMS1000 pinout
1  R8   - digit 9 (leftmost), button matrix, TSI-24 (ID3)
2  R9   - sound on/off switch, TSI-26 (ID4)
3  R10  - TSI-10 (START)
4  VDD  - -15V
5  K1   - button matrix
6  K2   - button matrix
7  K4   - button matrix
8  K8   - power supply for low battery indication
9  INIT - cap/diode
10 O7   - 7-segment DP
11 O6   - 7-segment G
12 O5   - 7-segment F
13 O4   - 7-segment E
14 O3   - 7-segment D
15 O2   - 7-segment C
16 O1   - 7-segment B
17 O0   - 7-segment A
18 OSC1 - OSC2 and 47 cap to VSS, 39K resistor to VDD
19 OSC2 - OSC1
20 VSS  - gnd
21 R0   - digit 1 (rightmost), button matrix
22 R1   - digit 2, button matrix
23 R2   - digit 3, button matrix
24 R3   - digit 4, button matrix
25 R4   - digit 5, button matrix
26 R5   - digit 6, button matrix, TSI-13 (ID0)
27 R6   - digit 7, button matrix, TSI-15 (ID1)
28 R7   - digit 8, button matrix, TSI-17 (ID2)


button matrix
    R0    R1    R2    R3    R4    R5    R6    R7    R8    R9
K1  0      1     2     3     4     5     6     7     8    --
K2  S      C     +     -   SPKR    .     X     M   SQRT   --
K4  9     +/-    =     %    --    --     /    --    --    ON