Date   : Mon, 01 Sep 1997 09:19:52 +0200
From   : "Mark Usher" <marku@...>
Subject: Re: 1770 disk controllers

Andrew

> Next: Does anyone have any information on the 1770 disc upgrade for
ModelBs?
> A circuit diagram would be useful, but an actual upgrade would be of more
use..
> Though, any information would be useful if I've got to work the thing out
for
> myself...

I have just followed this path myself. The fitting instructions are at the
BBC lives, which describes all the bits.

The hardest bit is the 1770 "module" that fits in the 8271 slot. I don't
have the circuit diagram from mine (Solidisk) but it shouldn't be too hard
too copy.
There are several versions though - Solidisk 1770 Issue 1 & 2 and also a
Solidisk 1770 & 8271 unit Issue 1 & 2.
The Issue 1 boards were apparently not so compatable with the Acorn ADFS,
indeed, I think I have an Issue 1 (hard to tell - it's not labelled), and
am having problems at the moment with the 1.30 ADFS although the 1.00 works
much better, apart from *MOUNT, probably one of the most important
functions :-(

I would also like to see a circuit diagram of the 8271 & 1770 board  -
anyone ?

Mark Usher