RTL Logic

From: Michael Holley <swtpc6800_at_comcast.net>
Date: Fri Jan 7 12:04:49 2005

My goal on the Tic Tac Toe machine was to build an exact replica of the Don Lancaster 1971 design. I have 2 of the MC789 inverters so I could build one unit.

I could change the design to use a TTL open collector inverter but it would be nice to have the exact circuit board. If I switched to TTL I could make the board or a kit available. (I figure a total market of under 10 units.)

The other item of a exact replica is the lamp color filters. The company AMP Hexseal still makes the filters (No.1813-27). I wonder how much they cost?

After two years of looking a found exact replacement JFET transistors (TIS58) for my TV Typewriter restorations. The generic replacement JFET worked but it is nice to have the exact part.

I got these parts on eBay for $1.35 plus $2.70 shipping.
13 TIS58 16 TIS97 7 L7805CV 2 L7808CV 4 L78N08 5 78L05A

Michael Holley
Received on Fri Jan 07 2005 - 12:04:49 GMT

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