[Coco] 6309 microprocessor project 01-13-2004

[jadonaldson at charter.net]

John,
  Have you looked at David Krell (sp) coco3 emulator. It 
runs under windows XP, but is only 128K. David has it as
a download on his web site. 

John Donaldson

> 
> From: "John Collyer" <johncollyer at zoominternet.net>
> Date: 2004/01/13 Tue PM 10:59:26 EST
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Subject: Re: [Coco] 6309 microprocessor project 01-13-2004
> 
> ----- Original Message ----- 
> From: "Roger Taylor" <rtaylor at bayou.com>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Tuesday, January 13, 2004 7:02 PM
> Subject: Re: [Coco] 6309 microprocessor project 01-13-2004
> 
> 
> > Good deal.  I just feel for you if you're converting Jeff's original code
> > which is designed for DOS only.  Yikes.  All of that dealing with segments
> > scares me.  You can do so much more and much easier by using the Windows
> > API, but you're probably finding this out already.
> 
> It seems I'm droping more of his code lately, and just using stuff that I
> wrote that
> works easily in masm32 and the flat memory model.
> 
> > I'm not sure what you're really wanting to do, so I can't suggest anything
> > specific.  But, I'm sure if you've made it this far, you'll come up with
> an
> > excellent idea for optimized address translation from the CoCo's GIME
> > scheme into a mere 2meg block of RAM you are guaranteed to get by the
> > malloc function in most PC compilers.
> 
> Thanks.  I'll get it together, and I'll make sure it is highly optimized!
> 
> > Precise timing is required for most of Sock's stuff.  There's too many
> > factors involved per user system that determines how timing-critical
> > programs and games behave.  Some of Sock's demos change video settings
> > while the raster beam is traveling down the monitor, without synchronizing
> > to HSYNC or VSYNC.  It is true that Sockmaster's real nickname should have
> > been "Syncmaster"... because he is a master of the CoCo's video system.
> It
> > doesn't surprise me at all if an emulator can't keep up with ole
> > Sock.  However, Sock's demos should be *THE* ultimate video test system
> for
> > the emulators.
> 
> That's my hope.  My emulator will be able to handle Syncmaster's demos.
> 
> > Nothing as far as I know is lacking from the M.E.S.S. emulator, but I've
> > always had problems with Jeff's emulator.  Please stick with the standard
> > format for .DSK and .ROM images which is to retain the pure image and not
> > chop off any null bytes at the end or anything else that would otherwise
> > show the file as being of a wierd size that a user can't directly look at
> > and determine what it might be for.  For instance, a 23k .DSK file means
> > absolutely nothing to me, but a 156k .DSK file speaks a common language to
> > everybody who sees it and knows anything about the CoCo disk system.  You
> > can even tack a small header to a 156k .DSK file and Windows will show it
> > as either 156k or 156 "point something", which is still very
> > revealing.  Let ZIP do the compression.  And by all means, choose
> > predefined formats for your images... it's bad enough that there are so
> > many .DSK formats that are totally incompatible or unrelated, such as the
> > DSHRINK .DSK format, Jeff's .DSK format, M.E.S.S.'s .DSK format, and
> > Microsoft has a .DSK format as well.
> 
> I am sticking to the way Jeff handled things with regards to ROM and DSK
> images.  I know about 16K or 32K rom images, howbeit they might be banked
> rom images with much more rom memory then just 16K or 32K.  I understand
> that these banked rom images write to $FF40 to switch the banks.  DSK images
> will be the JVC standard with no deviation.
> 
> John Collyer
> 
> 
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