Floating CMOS-TTL inverter inputs: pull up or pull down?

[undertone]

Hoping there are some digital folks here... I've built a MIDI switch box and it uses 74HC14 inverting Schmitt buffers. To simplify, it looks like this:

MIDI In -> Inverter -> Switch -> Group A -> Inverter -> MIDI Out 1A
                              |          -> Inverter -> MIDI Out 2A
                              |          -> ...
                              |
                              -> Group B -> Inverter -> MIDI Out 1B
                              |          -> Inverter -> MIDI Out 2B
                              |          -> ...
                              ...

Normally you ground an unused TTL input but if I ground an inverter the output is high. That kinda makes logical sense with MIDI since the line is kept high and data pulls it low. Not sure which it should be.

Second: if I switch off a group by disconnecting it from the input inverting buffer, I don't really care about the MIDI line being dead, and I'd rather save power because I'd like to be able to power the unit from USB.

So my questions are:

- Is it better in general to pull an unused inverting buffer input like the 74HC04 high or low?
- Which consumes less power: pulling the unused inverter input high or pulling it low? Or what difference is there?

Thanks!

[Tim Farrant]

Because the device is an HC or High Speed CMOS type, they draw very low power in either state so it would not matter if it is tied high or low. You can use a 10k ohm or higher value resistor to further minimize current draw.

[undertone]

Thanks for the info, Tim.