Date   : Wed, 19 Aug 2009 02:16:22 +0200
From   : rick@... (Rick Murray)
Subject: maximum econet packet size

Phil Blundell wrote:

> I was just a bit surprised that the fileserver would choose to use a packet
 > that large, but I guess L4 has no shortage of buffer space so it 
isn't too
 > implausible in that case.

Can you flag fill in the middle of a packet? Perhaps all the bridge 
needs to do is forward a small chunk at a time, like:

    source net               dest net

1. read chunk               inactive
2. flag fill                write chunk
3. read chunk               flag fill
4  flag fill                write chunk
5. goto 3 until done

Obviously it is more complex, but that's the essence of how a 
small-memory bridge could transfer a large file.

For what it is worth, I used an SJ bridge (6502 design, so no more than 
64K addressable) to transfer large files between an A5000 and an A3000. 
I think it was a bunch of Ovation documents, in any case we're looking 
at maybe 200K-ish apiece?


Best wishes,

Rick.

-- 
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...