JANET-derived Beeb Information
From the BBC Mailing List
(bbc-list-request@ohm.york.ac.uk)
Supplied to 8-Bit Software by:
Daniel Shimmin, Queen's College, OXFORD
(qu96001@ox.ac.uk)
Some of you will know that most (all?)
the universities in this country (and
the world...) are connected by
electronic networks (Unix and things).
Naturally computer enthusiasts tend to
exchange information through these
networks, and, not surprisingly, there
is a hard core of BBC enthusiasts still
in existence (they appear to be very
interested in the 32016 co-processor as
well, as it provides serious
programming facilities for your Beeb).
So anyway, here is such information as
has reached me, hopefully it will be of
use to some people out there (it's all
public domain by definition of course,
since it's been beamed around much of
the world) although it's mostly rather
technical for me. Very interesting
though, there seems to be a wealth of
information and knowledgeable people
out there.
If anyone wants to get in contact with
any of these strange and distant
people, let me know via 8BS.
================
From : Dave
(terros@sideways.welly.gen.nz)
I've upgraded my hard drive from 8 megs
to 20 megs. However, the new drive has
a track step time some 15 times faster
than the old! Time for a modified
version of ADFS to deal with this!
My hard drive boot program makes a copy
of the (Master) ADFS rom into a
sideways RAM bank and modifies it,
adding some code to set up the hard
drive specs every time Break is pressed
(my hard drive controller board
defaults to the correct number of
heads, but the wrong number of
cylinders).
This may be useless to all, as my setup
is not quite Acorn specification (the
SCSI->MFM controller board is a Seagate
device, rather than Adaptec, and has
head stepping options that may not even
exist on the Adaptec board). It'll
really be of most use to people trying
to hack their own hard drive systems
together.
Further to that, Acorn were kind enough
to send me the technical details of
their interface (1Mhz->SCSI), so of
anyone needs the info on an ADFS
compatible interface (i.e. the circuit
diagram), I have this here.
(DGS sez: Does this mean he has the
info to build a SCSI interface that can
just be plugged into the 1MHz bus? If
so, you could build one for next to
nothing, then just pick up a cheap
second-hand SCSI drive (they're
everywhere, very cheap), and you would
have a big HD system far cheaper than
anything else you could buy...any
thoughts anyone?)
================
From : Mik Davis at Aston Uni
(davism@uhura.aston.ac.uk)
Does anybody out there know anything
about writing Econet printer servers
software? I've been looking at this
recently and I thought of the following
points:
(1) I can pick up packets from the net
and print them but (a) how much data is
in each packet, (b) how do I know when
I have the last one?
(2) What do I do if another station
requests service whilst I'm still
servicing a previous request?
(3) Do I have to respond to a client
doing a *PS command, and if so, how?
I did post a message asking about
Econet printer servers on the net, but
all I got was a message from Acorn
saying "You can buy one from us for
forty pounds".
================
From : Walter Meyer, Physics Dpt.,
Pretoria Univ., S. Africa
(wmeyer@scinet.up.ac.za)
A local school has a number of BBC
Model B's with Amcom DFS's (using the
8271 FDC from Intel). Recently one of
the FDC chips blew. Since they would
like to keep the BBC's as similar as
possible, and would also like to
continue to use their Amcom DFS disks
(which seem to be incompatible with
anything else), they are not keen to
upgrade to a 1770 DFS.
I understand the 8271 is no longer
manufactured by Intel, but, according
to the local Intel agents, an
equivalent is manufactured by Intel
under a different part number. Does
anyone know what this part number is or
whether it or any equivalent by another
manufacturer exists? Any help would be
appreciated.
=================
Next, a few words of explanation.
Firstly, anyone putting the characters
:-) in their message is indicating that
whatever comes immediately before it
was meant to be sarcastic, ironic,
funny, not to be taken literally etc.
(Because if you look at those three
characters from the side, it looks like
a smiling face.) Similarly the
characters :-( mean "oh dear" or "how
sad" or something.
Secondly, many people begin their
messages by quoting whichever message
they are replying or responding to
(because it helps people to remember
what the original subject of the
message was), assisted by software that
provides for this. Normally, a repeated
message is indicated by adding ">" at
the start of each line, but I've used
quotes to make things easier. Thus you
can see (hopefully) how one message
follows another.
(Read the following, which starts with
a reply to someone else's message
(quoting it first), then continues with
someone else adding further comment to
the reply (quoting it first), etc. and
you might understand)
==================
From : Ian Stephenson
(ian@ohm.york.ac.uk)
"After revivig an old project, I hit
upon the solution (made easier by the
fact that I now have a Master with
Shadow Ram, which I didn't have
before). I've successfully doubled the
vertical resolution of the bitmapped
screen modes, giving a maximum of
640x512 in Mode 0.
"Having done this, I haven't any idea
what to do with it! :-)
"The refresh rate is effectively
halved, which seems to be too slow to
stop a certain amount of flicker under
the wrong conditions (isolated pixels
flicker). But it's not bad. Text looks
good.
"Anyone got any ideas for this?"
Excellent! I figure this works by
switching the banks between the
interlace, so lines from each bank get
interleaved(?). I had wondered if this
was possible, but don't have shadow RAM
to try it with (if this works well
enough, I might get some!). Once
selected how well does it sit with the
rest of the system (i.e. is it
transparent?), or are special drivers
needed? Will it work with any shadow
board?
The obvious thing would be to develop
some sort of windowing environment (the
old resolution wasn't really enough for
this). Once I get BCPL running I was
planning to add some O-O (DGS: I think
that might stand for Object-Orientated)
(as in Objective C) - I consider such
things essential for windowing. It
would then be pretty easy to get
something like the original Mac finder
up and running.
Have you tried converting the GIF
viewer to it? Mode 0 stuff looked
pretty good - twice the resolution
would be excellent.
Keep the text the same physical size,
but write some font drivers. Double
resolution would allow you to add
serifs and other cute features without
overly crowding things.
Acorn failed to see the graphics
revolution, and hence supprt for the
above stuff is limited. Therefore it's
probably something worth investigating
further.
=============
From : Martin Ebourne, Electronics,
S'hampton Uni (mje@soton.ac.uk)
"Excellent!...(DGS - he then repeats
the above paragraph)...Will it work
with any shadow board?"
Some bad news for you...this is Master
only. Beeb shadow RAM boards (at least,
the ones I've seen) are completely
different in operation. The problem is
that the 6845 is wired into the main
RAM, and needs to be because it is that
which carries out the refresh. Hence
the screen is always displayed from
main RAM. If you put shadow mode in,
the main RAM is paged out and shadow
RAM paged in, so all your data is
stored in there. Then OSWRCH is trapped
and the main RAM paged in before and
out again after. There is no physical
way of displaying the screen from the
shadow RAM.
I know this because I tried to do it,
and then had to disassemble the
controlling softwareto find out why it
didn't work. Obvious really. What
confused me is that the manual stated
clearly that the screen was displayed
from shadow RAM, but they are
definitely lying :-(
On the bright side, Master 128's are
quite cheap now... Ask Richard
Whitehand (who should be listening in
to this...), he's got half a dozen and
they are currently in his bad books, so
he's bound to be keen to get rid of
them. :-)
==============
From : Dmitry Petrov, Moscow State Uni,
via Russian ARM Support Group
(DPetrov@misis.msk.su)
Hello! I have a DOS filing system for
BBC B+/Master. It allows you to
read/write standard 360K PC disks.
(DGS: wow! :-) )
If anybody interested I could send you
the DOSFS by e-mail. Also I have some
other utilities for Econet, RAM FS.
I am interested in getting
communication programs for BBC/Master
(allowing 8-bit character set and X, Y,
Zmodem or Kermit protocols).
==============
From : Richard Whitehand
(R.W.F.Whitehand@uk.ac.loughborough),
Challenger BBS, Fast Viewdata,
v23/22/22bis/MNP2-5 - 24hrs - 021 445
3913
"I am interested in getting
communications programs for BBC/Master"
I have a whole set of these on my
bulletin board. Your best bet is the
"Aterm" series by Gareth Babb that do
black&white ANSI or 4-colour ANSI
terminal emulation, Xmodem, Xmodem-1k,
Ymodem, Ymodem-batch and Ymodem-batch-g
protocols...the terminal is pretty fast
too...should keep up to at least 9600
baud without problems... I don't think
anyone has written Zmodem for the Beeb
yet...besides, if you've got a reliable
link (e.g. an MNP modem) then
Ymodem-batch-g is just as fast in most
circumstances.
==============
OK that is about enough for now. If
there is any interest in this I have
lots more on a whole variety of
subjects (about twelve times as much
text as that above, and getting more
all the time), which can be included in
future 8BS issues.
Daniel Shimmin.