Much swearing - was Re: Do-It-Yourself PDP-11 help!

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Feb 16 17:57:44 2005

>
> Sellam asks:
> > But is it a problem if some lines are terminated and some aren't?
>
> If it's a small enough system to work reliably without termination
> (e.g., a single backplane), it will be fine even with some signals
> terminated. Technically that will introduce a small timing skew,
> but in the small system it won't be enough to matter.


One other point. You _must_ haev at least one terminating resistor
(either on the CPU or at the end of the backplane) on every signal. Just
letting one float high will not work. Remember the drivers are
open-collector devices

-tony
Received on Wed Feb 16 2005 - 17:57:44 GMT