Date   : Wed, 12 Nov 1997 20:49:29 +0000
From   : Dave Gilbert <gro.gilbert@...>
Subject: Re: Speeding up BeebEm

Chris Evans wrote:

> Aha! With sound support compiled in, my P225 MMX runs at pretty much
> exactly beeb speed. About 2/3 CPU is used under Linux/X, and this is
> pretty much split 50/50 between BeebEm and X.

P225MMX - Hmm...

Good; you can reduce the video update frequency via an environment
variable; 1 in 3 frames doesn't seem to do any harm to most games.
 
> One thing that would improve performance under X, is correcting the mode 2
> aspect ratio (as used by many games), so that pixels are half as wide in
> this mode. I'm about to hack this up in the next few days, and use mit-SHM
> if it isn't already. Maybe I'll get it working at 16bpp too, so I can take
> a screenshot of Linux running Quake (native), duke3d (dosemu), exile
> (BeebEm) and an Amiga game (UAE) all on the same display!

Mit-SHM is already used - on Linux it may be worth thinking about using
DGA extensions (Solaris as well) - thats direct video access under X.

> I'm happy to report that Exile now works under v0.8 of BeebEm!!! Amazing.
> There is minor bugginess in the sound code, however, as the cool Exile
> speech stops working bit by bit after a few "ouch"es said by the main
> character. The speech slowly gets truncated until it doesn't play any more
> :-( Other sound remains fine. Anyone know what I might have to look into
> to get this working?

I've got to be honest and say that I don't really know what is going on
after
version 0.6 (i.e. after anything on ftp.compsoc.man.ac.uk) - I've
not kept up with peoples hacks and improvements to my emulator.


Dave


-- 
 David Alan Gilbert - gro.gilbert @ treblig.org ---- by bread alone. He