Date   : Fri, 22 May 1998 23:14:56 +0100
From   : Crispin Boylan <viewtronix@...>
Subject: Ideas on new hardware

Hi

You may remember some ideas I was throwing around about High Density disks
with the beeb, ages ago, I've been doing some more thinking, and have come
up with this complicated but interesting (I hope) idea:

So, the idea: would it be possible for a new hardware board to be made
available for the BBC which allows it to do high density writing?  I
thought this would be a great idea, as with the ever decreasing
availability of 5.25 disks and also double density 3.5 disks, why not allow
the beeb to use high density?  As far as I can think of, and I have done
extensive reading about what you can and can't do with the BBC, there is no
major stumbling block.  One thing I have come across is really an
indecision, which Floppy Disk Controller to use!  You may or may not know
that some FDC's can only read, not write, single density, which is bad as
most beeb disks are single density (well all the DFS ones).  So, I decided
that maybe the Western Digital 37C65 which can write single and double and
high density disks would be the solution.  Is this, to everyones knowledge
a good choice?  Would another FDC be suitable, I had in mind the Intel
82078 but I cannot get enough specs on this device to make a complete
analysis of its capabilities.

I know there are people out there more knowledgable than me (like most of
you :) ) who like designing hardware for the beeb, so I am asking you this
to see if you think it is possible/feasible.  I could just about manage to
cobble together some hardware with a little help from various people (any
offers!?) but software I am completely stuck on, i have little knowledge of
programming DFS's, and as far as I can see a new DFS, ADFS and HDDFS (High
Density DFS, nifty eh?) would need to be programmed. Know any good
'DFSers'?  Another half-idea that I had would be to squeeze these three
DFS's together onto one chip, each one sharing common code, whilst being
individually selectable.  I would envisage the HDDFS to be a replica of
ADFS with the added bonus of being able to write 1.44mb disks, so perhaps
just ADFS and HDDFS could be put together?

Cheers,
Crispin Boylan - viewtronix@...

SWOS Page - http://easyweb.easynet.co.uk/~viewtronix
BBC Micro Games Archive - http://easyweb.easynet.co.uk/~viewtronix/beeb/

"I am, I am Superman, and I can do anything " - REM