20 Jan
2004
20 Jan
'04
5:12 a.m.
der Mouse wrote:
Looking at the DS3662 specs (now sadly obsolete), I'm wondering if the
DS3896 would work. I'm not comfortable driving the unibus with a stock
TTL output (hah, *which* ttl? :-) since I'd like the slew to be more
controlled (ok, slower). The "trapazoidal" drivers make for a nicer
edge.
I have not looked at QBUS specs (yet). I seems the drivers may be the same.
Is it terminated the same as a unibus?
-brad
From the looks of it, for a driver you can use
almost any
open-collector TTL output - at least, a quick look at the specs
doesn't
reveal anything that stands out as incompatible.
The receivers are a bit more interesting. The spec says that their
threshold must be between 1.3 and 1.7 volts and that their high-level
input current must be no greater than 80µA; it fails to give any limits
on how much current they source into a low-level input, though there
surely must be such a limit.