[Coco] Re: gcc-coco revisited

[Nathan Woods]

Roger Taylor writes: 

> It makes you wonder if they are using a BASIC compiler to write 
> M.E.S.S.  ;)   Ok, that's not fair, but it's true that the speed
> difference 
> in Vavasour's emulator and the CoCo modes in M.E.S.S. are much 
> different.  I only hope the M.E.S.S. team doesn't keep slowing things
> down.

LOL.  In any case, I can definitely say that MESS (and MAME) will never be 
as fast as a standalone emulator.  Jeff's emulator is written in highly 
optimized x86 assembler and MESS is written in portable C.  This alone does 
not explain the speed differences, because emulators like PC-Dragon (which 
are straight C) run well on a Pentium 90.  The other difference is that 
MAME/MESS have a lot of infrastructure to support multiple emulations.  The 
6809/6309 CPU core needs to be usable on both a CoCo, and a Joust arcade 
machine.  Portability is also another issue; there is an internal layer that 
the drivers write to which gets blitted to the screen, whereas Jeff's 
emulator can write directly to the PC's video RAM.  And on top of all this, 
there is a lot of processing going on to support mid frame video rendering.  
Unfortunately, this slows MESS down 95% of the time when someone isn't 
running a fancy game or a SockMaster demo.