Tape Beeper Readme ================== This circuit is a theoretical rebuild of the Tape Beeper for Commodore PET computers by HUH Electronics in 1978. It has not been tested in reality yet, but though it has been designed for the PET series of computers, it should in theory work with more or less any Commodore computer which has the 6 pin edge connector for the cassette interface. Note that it will not work on the Commodore Plus/4! See the original instructions ("Tape Beeper HUH Electronics") for more information. There is a PDF and text version of the file. This directory contains the schematics as being rebuilt (not the original schematics) as well as an iCircuit data file to run/simulate on the Apple Mac, iPhone or iPad. In addition to what the original instructions say, the resistor R4 in the schematic may be changed to manipulate the pitch of the tone. You may want to experiment with resistor values of about between 50k to 100k to have a reasonable pitch. However, you may choose whichever you wish of course. Here's a table with R4 values in kOhm and their resulting beeper frequencies in Hz (rounded at decimal point): R4 (kOhm) Freq (Hz) --------- --------- 1 2.6k 10 1.3k 20 1.0k 30 800 40 666 50 500 60 444 70 400 80 333 90 308 100 286 120 250 130 222 140 210 150 200 160 190 170 182 180 167 190 160 200 154 This table should give you a good idea of what value you might choose for R4. You can of course also put a potentiometer (varistor) it its place to adjust the pitch to whatever suits you best. Important: Do NOT include the resistor Rsim in a physical build! This resistor is for software simulation only and represents the cassette motor during simulation. Installation ------------ The installation is fairly simple. Simply connect GND to A-1, +5V to pin B-2 and the +6V motor line to C-3 of the cassette tape connector. This is all that is needed to be done. Source of idea to recreate the Tape Beeper: http://rick-melick.blogspot.ch/2013/01/my-personal-electronic-transactor.html