Date   : Thu, 30 Apr 2009 01:21:26 +0100
From   : bbcmailinglist@... (Ian Wolstenholme)
Subject: Biggest Econet Fileserver Yet??

I think the problem with larger Econet partitions is that the Level 3
initialiser needs a very large array calculated as being just over twice
the number of cylinders on the disc.  If the figure is anything more than
about 3,700 on a standard Beeb (or around 5,400 with a 6502 second
processor) then due to RAM constraints, there isn't enough available
memory for the DIM command.

I had been using the ARM7 co-pro to do the disc partition initialisation.
The utility runs without modification on the ARM7 as there isn't any
6502 assembler in it and there is an abundance of RAM to get round the
problem.

However, I've also tried it on a normal Beeb and as long as you keep
the number of cylinders below this number, it works.  To get the correct
partition size, you have to artificially adjust the number of heads and 
sectors per track but as I'm doing this using the very splendid Retroclinic
Compact Flash hard drive (shown here precariously balanced atop
the usual clutter: 

http://www.beebmaster.co.uk/Downloads/MegaNet3.jpg

)
I don't think it matters to the flash drive or the file server what disc 
geometry you put in as long as the correct partition size results.

All you need to do is modify line 360 of the L3 "WFSINIT" to something
like this:

360 discclylinders% 47:hds%=32:sectorspcyl%=hds%*32

This will give a 512MB partition (2047*32*32*256) and works on an
unexpanded Beeb, although you also have to REM out line 70 to stop
the detection for a second processor.

A problem with very large drives is the amount of space they take
up when the file server is running - after mounting the two 512MB
partitions, the server only had a cache of &FF7 bytes left, and
couldn't mount a third partition due to lack of RAM (hence the
internal error 5 in the picture earlier on).  Whether the number of
cylinders affects the amount of space in the file server is something
I need to investigate more to optimise available disc space and
server cache space.

Best wishes,


Ian



----- Original Message -----
From: michael.firth@... [mailto:michael.firth@bt.com]
To: bbcmailinglist@...,bbc-micro@lists.cloud9.co.uk
Sent: Wed, 29 Apr 2009 16:31:12 +0100
Subject: RE: [BBC-Micro] Biggest Econet Fileserver Yet??

> -----Original Message-----
> From: 
> bbc-micro-bounces+michael.firth=bt.com@... 
> [mailto:bbc-micro-bounces+michael.firth=bt.com@...
> .uk] On Behalf Of Ian Wolstenholme
> Sent: 29 April 2009 16:23
> To: bbc-micro@...
> Subject: [BBC-Micro] Biggest Econet Fileserver Yet??
> 
> Drool over this:
> 
> 
> http://www.BeebMaster.co.uk/Downloads/MegaNet.jpg
> 
> Best wishes,
> 
> 
> 
> Ian
> 
> 
Is that with a BBC platform as the server, or a 32-bit server?

If it is a BBC server, do you have a copy of the formatter? (as the only
ones I have barf with disks >64M)

Thanks

Michael