Date   : Mon, 04 Sep 2006 00:32:28 +0100
From   : "Ian Wolstenholme" <BBCMailingList@...>
Subject: Re: Tube File Copying

That's very interesting, I think I am getting to the bottom of this
gradually.

I created the "test file" through ADFS simply by using *CREATE
at the command prompt.

I also created an 8MB test file using *CREATE on the Master, 
which did it eventually but timed out during the operation because
the Archimedes was still creating the file at the time the
Master was expecting a response, although the file was there
and was readable to the end when the server started listening
again.

I went back to using "ADFSCopy" with a smaller buffer of about
1MB by changing the value of HIMEM (curiously the Arm Co-pro
seemed to get confused when I changed PAGE to 15,000,000
and wouldn't let me select the Source Directory, so I instead I
went for lowering HIMEM to 1,000,000).

This seemed to work OK until about 16MB had been copied and
then all kinds of errors came up, "Filecore in use", "Address
exception" etc etc. so I think the problem must be the 16MB
limit on file sizes on Econet, even though bigger files can exist
in parts of the disc which are accessible by the file server.

So I think the solution is going to have to be to knock together
a routine to copy these huge files in chunks of less than 16MB
with an option to set the "start point" in the original file to
get round any timeout errors and then when I've finally got
them all copied onto the A5000 I can stitch them back together
from there.

Best wishes,



Ian

----- Original Message -----
From: Chris Johns
To:  <bbc-micro@...>
Sent:  Mon, 04 Sep 2006 00:05:23 +0100
Subject: Re: [BBC-Micro] Tube File Copying

> There's no such restriction on Level 4 because it uses whatever
> local storage is available as determined by the Exports file; there
> is no concept of disc partitioning in L4 like L2/3. 

There is a restriction in the Econet protocols tho, in that all sizes
are 24 bit. Eg. the put bytes call only has 3 bytes for the file offset. There
was a later version of NetFS for RISC OS that supported longer
files by using 32 bit file addresses, I think with Advanced L4.

I've just looked in the PRM (2-964) which states that "File servers only
support files up to 16 Megabytes, so all pointer operations and file
length indications use 24it quantities... Econet protocols do not
support larger files."

How did you create your test file?
-- 
Chris Johns <chris@...             >