11 Mar
2010
11 Mar
'10
5:49 p.m.
On Mar 11, 2010, at 11:48 AM, Steve Maddison wrote:
There have been a lot of discussions about driver chips for Qbus
and Unibus here over the years, usually ending in frustration. Has
anyone tried to just do it with discretes? Nice little general-
purpos SOT-23 transistors, both bipolar and MOSFETs, are available
cheaply. Just a few days ago I bought a partial reel of 2N7002s,
just short of three thousand parts, for thirty bucks, and 1200
2N3904s for $10. What would it take to do this with 2N7002s,
2N3904s, or 2N3906s?
-Dave
--
Dave McGuire
Port Charlotte, FL
Ideally the
part that I want is similar to the 26s10 but it's non-bus
side signals are tri-state and LVTTL compliant. That would save
me a fair
number of parts.
Planning to drive and receive from a single pin, per chance? If
they'll take LVTTL on the driver input (which I'm hoping they will)
you could probably get away with one 5V-tolerant tri-state buffer on
the receiver output if the enables are used wisely. I was planning to
try such a set-up with a 74LVC244.