Date   : Fri, 07 Jun 1996 12:06:59 +0200
From   : deweger@... (Mark de Weger)
Subject: DFS buffer sizes?

I'm currently optimizing my PC <-> BBC serial file transfer program.
(The BBC part is the first Beeb program I wrote in 10 years!)
It would be helpful to know the answer to the following question:

  How large are the read and write buffers the BBC DFSs (DFS1.2
  would be all right; I don't guess there's a lot of difference
  between the different DFSs) set aside for bget/bput file 
  operations.

(To clarify the question: if you openout/openin a file and
then bput/bget a byte, the BBC doesn't write/read this single
byte, but probably a lot more. This is handy, because it speeds
up file access. The question is: how many more bytes does
the BBC read/write.)

I'd like to know the answer to the question because of the
following reason:
If the buffers are larger than, say, 2 pages, it is probably not
worthwhile to implement (larger) buffers myself in software:
the speed gain would be very small.  If, however the buffer
sizes are only, say, 1/2 page, it might be worthwhile to implement
to implement buffers myself.

Thanx,
Mark.