[Coco] Could MESS CD-i emulation be hacked to MM/1?

[Joel Ewy]

Apparently the latest version of MESS has "reasonable CD-i emulation":  
http://cdii.blogspot.com/2009/11/latest-mess-includes-reasonable-cd-i.html

It appears that there is now enough CD-i hardware emulation to run 
Lemmings and some other games.  This means that the Video / System 
Controller hardware is present in at least some rudimentary form, which, 
along with the CPU and OS-9 operating system, is what the MM/1 shared 
with CD-i.

Though it appears to be in an early stage, this is certainly an 
interesting development.  It would be very nice to be able to run MM/1 / 
TC-70 software in emulation.  In fact, an OS-9/68K emulation machine 
based on the CD-i would have much better graphical capability than the 
real computers did.

It looks like MESS may already have support for:
68901 MFP (from the Atari ST)
68681 DUART
WD33C93 SCSI Controller (From Amiga 3000)
NEC765 FDC (Is this register compatible with the WD37C65 used in the MM/1?)

The only major chips I see that the MM/1 has that don't appear already 
to be emulated in MESS are the 68230 (which is essentially a glorified 
PIA with timer) and the AD7569 ADC/DAC chips.  The 7569 certainly isn't 
required to boot OS-9, and I think the 68230 is just used for parallel 
ports, though I'd have to look at schematics again to be sure.

It looks as if it would almost be a matter of gluing together some 
blocks that are already present in the MESS codebase to get something 
that would boot OS-9 from an MM/1 disk image.  I haven't really looked 
at the MESS code, and my C is fairly well oxidized K&R, but I do have a 
working MM/1 and plenty of MM/1 technical information.  I know Tim 
Lindner has been involved with the MESS CoCo port.  Surely there are 
enough capable and motivated people on this list to make a go of it...

JCE