16 Jan
2004
16 Jan
'04
3:45 a.m.
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