Radio Shack Monkey See Chip labeled MP0271 MSL^ 8214 die labeled 1000E MP0271 18 buttons: 0-9, ., C, +, -, x, /, ? , = 2 LEDs: R and G piezo TMS1000 pinout 1 R8 - N/C 2 R9 - N/C 3 R10 - N/C 4 VDD - 9v- via switch 5 K1 - button matrix 6 K2 - button matrix 7 K4 - button matrix 8 K8 - button matrix 9 INIT - N/C 10 O7 - G LED 11 O6 - R LED 12 O5 - N/C 13 O4 - N/C 14 O3 - N/C 15 O2 - N/C 16 O1 - N/C 17 O0 - N/C 18 OSC1 - connected to OSC2 and 47pF disc cap (to VSS) and 68K resistor (to VDD) 19 OSC2 - OSC1 20 VSS - 9v+ 21 R0 - button matrix 22 R1 - button matrix 23 R2 - button matrix 24 R3 - button matrix 25 R4 - button matrix 26 R5 - piezo 27 R6 - N/C 28 R7 - N/C button/switch matrix K1 K2 K4 K8 ------------------------------------------ R0 0 1 3 2 R1 4 5 7 6 R2 8 9 -- -- R3 x / + - R4 = ? C .