Date   : Sun, 22 Jan 2006 16:09:59 +0000
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: eBay What is this?

Jules Richardson <julesrichardsonuk@...> wrote:
> There's possibly some very interesting data on it, given that Cumana boards
> are extremely rare and would likely have only been used in specialist
> applications.
> 
> If you can get a raw disk image to me it'd be much appreciated
(unfortunately
> the necessary BBC BASIC commands to get such an image is beyond me!) - I've
> got a Cumana board here (but so far have been unable to figure out how to
set
> the drive geometry in its NVRAM, so I'm not quite at the point where I can
> just plug in a drive and go!)
 
Unfortunately, the ADFS OSWORD &72 sector commands refuse to work
if a drive has not been mounted. Doublely stupid, ADFS refuses to
MOUNT a drive if it does not have an ADFS filesystem on it.
 
With floppies it's easy to get around this. Insert formatted disk,
*MOUNT it, swap to non-ADFS disk, use OSWORD &72. Unfortunately,
you can't do this with a fixed drive :(
 
The only way to do it is to feed SCSI commands directly to the
hardware, which, at the moment, is a bit beyond me. You might like
to browse through the ADFS 1.50 disassembly at
http://mdfs.net/Info/Comp/BBC/ADFS for inspiration. It might be
possible to jury-rig some code that pages the ADFS ROM in and
calls the low level code, bypassing the OSWORD &72 checks.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
Spectrum Emulators - http://mdfs.net/Apps/Emulators/Spectrum