Date   : Tue, 18 Apr 2006 13:51:00 +0100
From   : "David Harper" <dl.harper@...>
Subject: Re: CPFS and MOVE

Jonathan Graham Harston wrote:


>> You might just also get it from having duplicate filing system ID 
>> numbers.
>> Use *OPT 7 in CPFS to set the Filing System ID to something unique. The
>
> I would recommend 11 as nothing else (seems to) use that.
> Documentation lists "Acorn WDFS", but after extensive searching I
> haven't found out what it is.

I will accept that.

CPFS defaults to a value of 5, which is the same as NFS. The reason for that 
is the way that Computer Concepts designed InterWord (and its companion 
programs). This program would only use the full filing system facilities if 
the FS ID was equal to 4, 5 or 8 (DFS, NET or ADFS). If any other FS ID 
value was used, then InterWord would only access files using single byte 
accesses (OSBPUT and OSBGET rather than OSGBPB) making it incredibly slow, 
it would not display the filing system catalogue, etc.

We had to choose whether to do things properly and use a unique ID number - 
this would please the purists but annoy all InterWord users - or to adopt a 
compromise. We chose the latter option, using 5 as the default because most 
512 users needed one or both DFS and ADFS, whereas a much smaller number 
were on a network. There seemed to be fewer Econet users than InterWord 
users. The *OPT 7 option was included for any who wanted to use a network.

This was a kludge, I agree, but the fault really lay with Computer Concepts. 
When one is writing a service program, one has to work with the failings of 
other programs that might want to use it.

David Harper