On Thu, 24 Feb 2005, Alan B. Pearce wrote:

>> I seem to remember using 74LS245s for the bus interfaces -
>> as I remember they are tri-state, and it should be possible
>> to keep them in high-impedance state with pull-whichever
>> resistors until the PIC is ready to talk to someone else.
>
> There are buffers available designed for hot-swap use which are guaranteed
> to keep the bus in a Hi-Z state until properly enabled I am not sure if
> these are the ones that Jinx stated in his original post, and I don't have
> any part numbers to hand.

Afaik all 74LSxxx series bus drivers with tristate outputs are 
hot-pluggable. Afair you cannot inject current into the Vcc line through 
an output of this kind. The bulk diode is not there etc.

Peter
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