hardware description and pinout
Scans of the PCBs: PCB 1 PCB 2
There are 6 control signals from the TMS1007 to the TSI speech chip; 5 to select the word to speak and 1 to begin speaking. Of the 32 possible words, 24 are used. A 2K mask ROM holds the speech data. mask ROM data mask ROM dump
Logic captures of the mask ROM signals while pressing the buttons M, +, 1, 2, 3, =, sqrt, -, 4, 5, 6, %, X, 7, 8, 9, C, /, ., 0, x/-, S, then M 4 times. The last 2 times M was pressed, the word "overflow" was spoken. address signals data signals
Speech chip die shot from siliconpr0n
About the development of the calculator
