On Jan 15, 23:08, Tony Duell wrote:
> I beleive you are correct. One state is a -ve voltage between -3V and
> -25V, the other is a +ve voltage between +3V and +25V. Anything
between
> -3V and +3V is undefined.
My data sheets agree with that.
> [Actually, I'll admit to having fed the output of an HCT04 (or
similar)
> into a serial port once. My excuse it that it waas a one-off test
board,
> and I had the schematics of the serial card it was driving (which
showed
> a 1489 reciever).
I once used a dual opamp in an 8-pin DIL to do that. One half was the
receiver, one the driver. I knew that what I was driving wouldn't
overload the opamp's output, and it kept the chip count down (it was a
small microcomputer based on a Z8, on a board about 3" square).
> No way would I do this in a device to be used by others!)
Ditto!
--
Pete Peter Turnbull
Network Manager
University of York
Received on Fri Jan 16 2004 - 03:45:55 GMT