Path: utzoo!attcan!uunet!husc6!bloom-beacon!tut.cis.ohio-state.edu!rutgers!att!mtuxo!mtgzz!drutx!druhi!dlm
From: dlm@druhi.ATT.COM (Dan Moore)
Newsgroups: comp.sys.amiga
Subject: Re: Mac emulator!?
Message-ID: <3729@druhi.ATT.COM>
Date: 21 Nov 88 16:43:11 GMT
References: <5817@polyslo.CalPoly.EDU>
Organization: AT&T, Denver, CO
Lines: 59

in article <5817@polyslo.CalPoly.EDU>, nschultz@polyslo.CalPoly.EDU (Ned W. Schultz) says:
> I was a little surprised to hear from my father that he had seen a
> Mac emulator for the Amiga at the World of Commodore show held in
> Philadelphia.  Finally tracked down the company from the show program
> and discovered that it is ReadySoft, the folks who have a 64 Emulator
> (and the folks marketing Dragon's Lair).  I called them yesterday to
> confirm this and the girl on the phone said, yes, we have an emulator
> and it will ship the first week of February (1989, I am guessing).  She
> is sending a flyer or brochure.

	The ReadySoft emulator was developed by a programmer in New
Zealand.  He talked to several companies before deciding to use
ReadySoft as his publisher.

	The product supports both the 64K and 128K ROMs from the Mac. 
The 64K ROMs are currently selling for about $25 to $50 per set (2
chips), the 128K ROMs are about $100 per set.  With the 128K ROMs almost
all Mac software will run, the only failures will be due to hardware
differences (ie.  the Mac program went directly to the Mac hardware
instead of using the standard ROM routines). 

	The biggest limitation is memory, the Mac OS doesn't support
non-contiguous RAM.  So on a 1000 you can have 512K Mac since the
support code is loaded in the WCS.  On the 500/2000 you are currently
limited to 256K or so since the emulator code is loaded in the first
512K along with the "Mac's" memory.  By moving the emulator code out of
the first 512K you could have a 512K Mac.  With the 1 meg of chip RAM
(whenver that becomes available) you will be able to have 800K to 1 Meg
Macs, depending on where the emulator code is loaded.

	Unfortunately HyperCard, the program most people want off the
Mac, requires 750K to run.  Until more memory is available to the Mac
the emulator won't be able to run it, or some of the other large Mac
programs.

	The emulator can read part (about 30 tracks) directly off a Mac
disk.  The data rate on the other tracks is too high for the Amiga
floppy controller to handle (you are trying to read a track written at
350 to 600 RPM in a drive spinning at 300 RPM).  This gives a reasonable
way to transfer programs and data from a Mac to the Amiga. 

	The emulator will either run in interlace mode (640x400) or
non-interlaced mode (640x200).  In non-interlace mode you see only half
of the actual screen.  Moving the mouse from one half to the other
causes the display to change.


	NOTE: Some of the above is almost positively wrong.  It is based
on my use of an early version before the programmer contacted ReadySoft. 
Some/all of the limitations may have been removed or changed.  If the
programmer has found a way around the memory limitations it is going to
be a great product. 



			Dan Moore
			AT&T Bell Labs
			Denver
			dlm@druhi.ATT.COM