Date   : Tue, 26 Sep 2006 13:19:12 +0100 (BST)
From   : "Richard Gellman" <splodge@...>
Subject: Re: File access 'M' on MDFS

Hi,

The following snippet showed up on Google Groups:

[snip]
It has no effect, merely reflecting the 8th bit in
the access byte.

I believe we picked "M" to stand for "Multiple", as we were
thinking of a scheme to allow more than one client to open
the same file with write access (overriding the normal
one-writer/multiple-reader locks).  However, this was never
implemented.

I can't be 100% sure of the above - it is hard enough after
so many years to remember the things that we actually did,
never mind things we were only thinking about doing....
[snip]

Further posts down the chain confirm this is the case.

Seems like it was a feature that never got implemented.

-- Richard

> I have looked through all my 4 copies of the MDFS manual and I
> can only find the reference in the error list on page A-7.  I can't
think what "M" would stand for unless it's Manual or MDFS.  Maybe it is
some special kind of access used for system files like
> %PASSWORDS ?
>
> There are quite a few errors and omissions in the MDFS manual
> (see *CREDIT topic earlier) and I have just noticed on the previous page
that it says there are 4 possible reasons for a "Drive read only" error
and then goes on to list only 3!!
>
> There is a PDF version of the MDFS Manual at BBCDocs, I don't know if
you can do a text string search within PDFs but if you can it might turn
up something quicker than reading it from cover to cover.
>
> Best wishes,
>
>
>
> Ian
>
> ----- Original Message -----
> From: jgh@... (Jonathan Graham Harston)
> To:  bbc-micro@...
> Sent:  25 Sep 2006 23:25:28 +0100
> Subject: [BBC-Micro] File access 'M' on MDFS
>
> Does anybody know what setting a file's access to 'M' does on the MDFS,
settable with *ACCESS filename +M:
>
>>*INFO FRED
> FRED       FFFF1200 FFFF802B   00119A WR/r  today today 02:49 100 (100)
>>*ACCESS FRED +M
>>*INFO FRED
> FRED       FFFF1200 FFFF802B   00119A MWR/r today today 02:49 100 (100)
>>
>
> All file operations seem unchanged. I have trawled through the
> MDFS manual several times and only found two references to it, in that
NetFS_Examine returns the 'M' bit in the access byte, and it is listed
in the allowed characters for the *ACCESS command in the list of errors.
>
> --
> J.G.Harston - jgh@... - mdfs.net/User/JGH
> The most perfect world is an imperfect world as the imperfections give
people a reason to strive to change it.
>
>