Tandy Zing-O Chip labeled TMS1000NLL MP0166 MBS 8001 SINGAPORE 2 buttons 22 LEDs 2 7-segment LEDs piezo fast/slow switch TMS1000 pinout 1 R8 - button and switch common 2 R9 - piezo lead 1 and 1K to VDD 3 R10 - piezo lead 2 and 1K to VDD 4 VDD - battery - 5 K1 - Shoot button 6 K2 - Stop button 7 K4 - N/C 8 K8 - Fast / Slow switch 9 INIT - VDD 10 O7 - N/C 11 O6 - segment G 12 O5 - segment F and LED 6 13 O4 - segment E and LED 5 14 O3 - segment D and LED 4 and column 1 (right) 15 O2 - segment C and LED 3 and column 2 16 O1 - segment B and LED 2 and column 3 17 O0 - segment A and LED 1 and column 4 (left) 18 OSC1 - 47pF disc cap to VSS, 47K resistor to VDD 19 OSC2 - OSC1 20 VSS - battery + via switch 21 R0 - LED row 4 (top) 22 R1 - LED row 3 23 R2 - LED row 2 24 R3 - LED row 1 (botton) 25 R4 - digit 1 (right) 26 R5 - digit 2 (left) just segments B and C 27 R6 - LEDs 1-6 28 R7 - N/C LED Layout O0 O1 O2 O3 ----------- 5 6 4 R0 o o o o 3 R1 o o o o 2 R2 o o o o 1 R3 o o o o