Date   : Wed, 14 Oct 2009 12:05:30 +0100
From   : michael.firth@... (michael.firth@...)
Subject: New storage system suggestinons?

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> From: 
> bbc-micro-bounces+michael.firth=bt.com@... 
> [mailto:bbc-micro-bounces+michael.firth=bt.com@...
> .uk] On Behalf Of me@...
> Sent: 14 October 2009 11:58
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> Subject: Re: [BBC-Micro] New storage system suggestinons?
> 
> On 14 Oct 2009, at 11:50, Joel Rowbottom wrote:
> 
> > Sorry, I meant via *EXPORT and *IMPORT.
> 
> Oh. Er, maybe. I just assumed you could. Maybe not. Probably not,  
> actually, as the RAM disks wouldn't be big enough.
> 
I think the biggest limitation at the moment will be that RamFS is derived
from a DFS filing system, rather than an ADFS one.

The RAM capacity could be an issue too, as to emulate two ADFS floppies you'd
need 1280K of RAM, so I suspect any ADFS floppy emulation would be limited
to a single drive (as I think the DataCentre RAM is only 1024K)

As you don't get many things that depend on absolute paths in ADFS (i.e. 
games), then generally an ADFS floppy can be handled by just putting the 
contents in a directory on an IDE CF. One thing that would help with this
(that I don't think exists yet) is a utility to force ADFS to treat a sub-directory
as if it were $ (effectively an equivalent of the Unix "chroot" for ADFS)

What I would really like is a system to allow me to use a file on the IDE
disk as a filesystem - i.e. versions of DFS (and less importantly ADFS) that
will just read sectors from the IDE disk, rather than from a physical disk
or RAM disk.
I don't think it should be that hard for DFS, just re-direct the disk access
code through OSWORD &72, and store the starting sector of the CF file somewhere
to add as an offset.
Sadly I don't have the time to hack at this at the moment...

Regards

Michael