Date   : Tue, 02 Jun 2009 07:25:32 -0500
From   : jules.richardson99@... (Jules Richardson)
Subject: BBC Master SCSI

Darren Grant wrote:
> I realised this morning that I'm way out of date in electronics these days.
> I had a go with building a CPLD design but found myself way out of my depth.
> There was a time when I would have enjoyed figuring it out but now I realise
> I don't have the patience or inclination anymore.

Hmm, aren't there sufficiently few LS IC's to the Master SCSI I/F that if you 
just want one in a hurry, glue the darn chips upside-down to any old scrap bit 
of sheet* and run wires between the legs? :-) It'd be about as inelegant as 
it's possible to get, but at least you'd have a SCSI I/F in about 30 mins, and 
could buy/build a more robust and professional version when one was available.

* although there's nothing wrong with doing that on a proper bit of 
stripboard, either, would would at least be reasonably strong.

The original Master interface ignores /ATN, /DBP etc. and it'd be nice if any 
modern solution at least provided these at the hardware level (with the hope 
that someone could throw together suitable software further down the line) - 
so any professional board perhaps isn't as simple as taking the existing 
schematic and reproducing it.

p.s. I might actually have some Domesday time later this week!!

cheers

Jules