Date   : Tue, 27 May 2003 01:04:43 +0100
From   : Mike Tomlinson <mike@...>
Subject: Re: B+ shadow RAM query

In article <NGBBJEBJCLGDHJPEPGHECEPBCFAA.martin@...>,
Martin Rigby <martin@...> writes

>According to David Atherton's Master OS Guide, the OSBYTE command you are
>referring to appears to be &71 (113) :-

>Does this help?

Certainly rings a bell.  There's a DFS disk image here (7.6k):

http://www.astro.livjm.ac.uk/~mdt/gen15.ssd

It contains the following files:

Maslogo, Mcpixdr, Pixdata, Compact (chain "maslogo")

BBCcube (chain "bbccube")

Maslogo draws the Master logo and then overlays the Compact logo.  It
will not work properly on a BBC B but runs fine on BeebEm in Master
mode.  I think it uses the extended graphics VDU commands available on
the Master (the forerunner to this was the GXR ROM for the BBC B.)

BBccube uses shadow RAM bank flipping to create a smooth animation of
spinning cubes.  Or at least it would, if I had not hacked the program
to make it work with my Watford RAM board.  The "*WATRAM" and "*BEEBRAM"
commands were in a ROM I wrote - all they do is the equivalent of
*FX113,0 and *FX113,1 discussed above to flip between RAM banks to
achieve smooth animation.  This is the file &.myrom referred to in line
20 which should be deleted.  So it should be possible to make the
program work on BeebEm in Master mode with a couple of mods.  I tried,
but always got flickering.  Not sure whether this is due to BeebEm.

I tried to find an original copy of the program but don't have it, and
it doesn't appear to be on the Master Compact welcome disc images at
8bs.com.

Mike