DEC bus transceivers

[Al Kossow]

On 10/23/16 11:50 AM, shadoooo wrote:

> The problem is that there aren't open drain bus transceivers, but the
> problem could be solved simply using input-only and output-only components,
> connecting two in parallel but opposite direction on bidirectional pins.
> 

The reason for using the old parts is the logic thresholds are unique to
the Unibus to handle worst-case bus loading and the termination voltage they
used.