----- Original Message -----
From: Hamid A. Wasti <[EMAIL PROTECTED]>

>
> If that is really the case, then you do not need to tie the input external
to
> the chip :-)   The internal pullup resistor will pull the input to a high
> state


Hamid,
I agree with you, what is the purpose of using the external resistor for
cmos if the resistor is internal.  I have always asked that question, I
don't know the answer.

Jon wrote:
No, if you check this with a DVM, you will find there is NO resistor
to either power rail on generic 4xxx,  ....

.Look at the low level schematic provided by the Mfg for their integrated
circuit.   The input MUST, I repeat MUST be biased for the FET, transistor
or any semiconductor to work.      It may be biased with another semi device
but it will be  biased. If it is biased with a Semiconductor then your DVM
measurement would not work.
This is my last comment on this because I agree we are hogging up the server
with non Protel issues.

Mike Reagan
EDSI
Frederick

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