On 23-5-2010 16:38, Orchid XP v8 wrote:
> scott wrote:
> 
>> You should never be leaving any inputs as floating anyway, that's just 
>> asking for trouble (for example if you use a different IC series 
>> later). Best to always tie your inputs to whatever you want them to be.
> 
> So what might be a good value for a pull-down resistor then?
> 
> (4.5V supply, 74HCxx ICs.)

There is seldom a need to use a pull-down resistor at the input. You can 
simply connect it to the ground. With e.g. a 7400 you can connect both 
inputs together in stead of one to the positive power supply line to get 
functionally an inverter (that is often easier to route than the 
alternative).

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