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Vintage threads from the first ten years

previous: GFR The input ballance (and other parts... -- 5/28/1999 8:27 AM	View Thread

Re: Ultimate DIY debugger award/IT IS OVER!

5/28/1999 10:46 AM
GFR	Re: Ultimate DIY debugger award/IT IS OVER! I took a look at a National data book. The National chip doesn't have a "protection" transistor like the Q18 in Motorola. The National is different from the Texas in that in the Texas the ballance pins connect to a ~1K resistor to ground and the emitter of a transistor, while in the National they connect to a 100R resistor to ground and a 2K resistor to the emitter of the transistor. So the National works, but maybe the original Texas works better.

5/28/1999 10:46 AM

GFR

Re: Ultimate DIY debugger award/IT IS OVER!

I took a look at a National data book. The National chip doesn't have a "protection" transistor like the Q18 in Motorola. The National is different from the Texas in that in the Texas the ballance pins connect to a ~1K resistor to ground and the emitter of a transistor, while in the National they connect to a 100R resistor to ground and a 2K resistor to the emitter of the transistor. So the National works, but maybe the original Texas works better.