Date   : Sun, 24 Aug 1997 13:48:59 +0100
From   : Mike Tomlinson <jasper@...>
Subject: Re: BBC Micro Disk Drives and PC disk drives

In article <33ff6d37.9097611@...>, Andrew de
Quincey <adq@...> writes

>I've connected the drive, but when I do *CAT on a disk, the drive
>spins up, and just sits there... not moving it's heads or anything....

If the light comes on as soon as you turn on the BBC, the cable is
attached the wrong way around.  If the light doesn't come on at all, you
have the drive select jumper set incorrectly.  It should be set to 0
(for drives using DS0-3) or 1 (for drives using DS1-4)

You may also need to experiment with the RDY link if one is present.

>Does DFS 1.20 assume you have a 1770 disk controller? 

No, it's for the 8271.

>The machine has
>a 8271 installed.. Does anyone know what DFS'es used the 8271? 

Acorn DFS 0.90, 1.20
Watford DFS 1.43, 1.44 (note: DFS, not DDFS)

>I was
>considering trying Watford's DFS v1.4 from the site.... mainly because
>it has a *FORM command in the ROM....

1.43 doesn't have the Tube host code, 1.44 does and so some of the error
messages are much more abrupt (to make room for the extra code.)  If you
don't have a second processor, I'd recommend 1.43.

>Or does anyone know where I can get my hands on a 1770 upgrade for the
>BBC B? 

Someone reading this will probably offer you one...

>The upgrade manual  implies that the upgrade is a board with
>several chips on it

The board plugs into the 8271 socket and holds 1770 and a couple of
74LSxx TTLs.  You also need to make other changes to the main board,
depending on whether DFS and/or Econet was previously fitted or not.
And a DFS ROM with 1770 code (Acorn 2.00 et seq, Watford DDFS)

>, i.e. not just as simple as replacing the 8271
>with a 1770 chip...

8271 is 40 pin, 1770 is 28 pin.  Not a straight swap.

-- 
Mike Tomlinson
~@...[127.0.0.1]