14 May
2015
14 May
'15
7:52 p.m.
On Thursday, May 14, 2015 at 14:21, Marc Verdiell wrote:
Thanks a million!
You're welcome.
As for the receivers, it can go into straight TTL
apparently, I read
that somewhere in an HP manual.
Both TTL and LSTTL (but not STTL or HTTL) will work with an appropriate
pulldown resistor. LSTTL is recommended for the lower power and improved
speed over TTL. The pulldowns are necessary to guarantee logic zeros when
driven by the original CTuL or newer 75121 parts, which have open-emitter
outputs.
Section 5-7, "Computer Backplane Assembly Requirements," of the
aforementioned interfacing manual details the recommended circuits.
-- Dave