PDP-11/94-E

[Paul Koning]

> On Jun 2, 2016, at 2:19 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 
>> ...
>> For whatever reason they managed to disable the unibus  I/O
> 
> I'm not sure you can (in hardware terms, that is - and clearly if there's no
> way to do it in the hardware, the software cannot do so)... although it could
> be broken.

I could imagine any number of signals that, if stuck, would make the bus inoperative.  Reset asserted, for example.  Or AC LO or DC LO asserted, possibly.  Or NPG asserted.

	paul