Date   : Sat, 21 Apr 2007 22:33:16 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: BBC B progs on a B+128k - any known problems?

>Message-ID: <609102.59595.qm@...>
 
Greg Cook <debounce@...> wrote:
> > problems trying to stop OSWORD &7F trampling all over page &10
> 
> Yeah, I've seen it cause problems.  To fix it the DFS should only need
> to claim the workspace (and restore its contents) on receiving disc op
 
DFS /does/ claim the workspace when it is used. It's /OSWORD &7F/
that tramples over the workspace. It should /never/ be using the
shared workspace, it's a device driver, not a filing system.
 
> If the DFS can't be patched then the workspace *will* be corrupted when
> the user calls OSWORD &7F etc., but other ROMs can anticipate the
> damage and relinquish it temporarily when they make the call themselves
 
That causes even more problems. An application owns the shared
workspace and wants to save it to disk. It calls OSWORD &7F.
OSWORD &7F claims the shared workspace. The application tries to
flush the contents of the shared workspace to disk, so calls
OSWORD &7F to save it to disk. OSWORD &7F claims the shared
workspace. The application tries to flush the contents of the
shared workspace to disk, so calls OSWORD &7F to save it to disk.
OSWORD &7F claimes the shared workspace. The application tries to
flush the contents of the shared workspace to disk, so calls
OSWORD &7F to save it to disk....
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for the Sinclair Spectrum - http://mdfs.net/Software/Spectrum