Date   : Fri, 22 Nov 2002 03:09:48 +0000
From   : "W.Scholten" <wouter.scholten@...>
Subject: Re: solidisk dfdc + dual drives

L.S.

My DFDC is an issue 1, and after some experimenting:

Used a 74LS00 as an inverter:
 - pin 6 of connector that goes in the 8271 socket on the BBC PCB
(=drive sel 1) -> invert -> pin 2 (=drive sel 1).

Gives a mess of wires but now both drives work!

What's supposed to happen if ds0 and ds1 are selected? Should a drive
check if there's a higher one and not act? or not? In any event, the
issue 1 DFDC doesn't work with mitsubishi drives from 1983 so it seems a
badly designed board (unless it's a prototype but I don't think so).

I've made some images but due to PC (HD actually) trouble it may take a
while before I place them on my pages.

Wouter

-- 
BBC/atom/old magazine scans etc:
http://www.astro.livjm.ac.uk/~bbc/