Unibus disk controller with modern storage

Paul Koning paulkoning at comcast.net
Fri Oct 21 14:11:00 CDT 2016


> On Oct 21, 2016, at 2:50 PM, Guy Sotomayor Jr <ggs at shiresoft.com> wrote:
> 
> 
>> On Oct 21, 2016, at 11:41 AM, Paul Koning <paulkoning at comcast.net> wrote:
>> 
>> 
>>> On Oct 20, 2016, at 6:05 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
>>> 
>>>> From: David Bridgham
>>> 
>>>> the right threshold voltage to meet the receiver spec
>>> 
>>> The UNIBUS spec says the 4 crucial receiver parameters are input thresholds
>>> (high and low), and the input currents (high and low); the crucial
>>> transmitter parameters are the output low voltage (at 50 mA sink), and
>>> the output high leakage current.
>> 
>> Where did you find those specs?  I see a Unibus Spec on Bitsavers, but it doesn't appear to mention the electrical specs.
>> 
> 
> They exist in various DEC handbooks.  I don’t recall which one had them.

Found it.  1976 Peripherals Handbook, page 6-4.  It specifies the driver output low voltage at 70 mA sink, not 50...

	paul




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