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

[Eric Smith]

I wrote:
> 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.

Pete wrote:
> You're assuming the CPU still provides termination at its end.  Without
> that, the lines will be floating.

Good point!  Here the fact that DEC specially selected low-leakage
driver, receiver and transceiver chips works against you.  The
roughly TTL-compatible inputs will pull up for you, but very weakly,
so if there's no termination at either end of the bus, the system may
be unreliable.

Eric