Solid State Disk replacement for RD53, 54, RK05, RL02/02

[Dave McGuire]

On Mar 11, 2010, at 11:48 AM, Steve Maddison wrote:
>> Ideally the part that I want is similar to the 26s10 but it's non-bus
>> side signals are tri-state and LVTTL compliant.  That would save  
>> me a fair
>> number of parts.
>
> Planning to drive and receive from a single pin, per chance? If
> they'll take LVTTL on the driver input (which I'm hoping they will)
> you could probably get away with one 5V-tolerant tri-state buffer on
> the receiver output if the enables are used wisely. I was planning to
> try such a set-up with a 74LVC244.

   There have been a lot of discussions about driver chips for Qbus  
and Unibus here over the years, usually ending in frustration.  Has  
anyone tried to just do it with discretes?  Nice little general- 
purpos SOT-23 transistors, both bipolar and MOSFETs, are available  
cheaply.  Just a few days ago I bought a partial reel of 2N7002s,  
just short of three thousand parts, for thirty bucks, and 1200  
2N3904s for $10.  What would it take to do this with 2N7002s,  
2N3904s, or 2N3906s?

              -Dave

-- 
Dave McGuire
Port Charlotte, FL