Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!shadooby!samsung!uunet!zephyr.ens.tek.com!orca!pogo!kevind
From: kevind@pogo.WV.TEK.COM (Kevin Draz)
Newsgroups: comp.sys.mac
Subject: Re: Soft PC (for the Mac)
Message-ID: <8151@pogo.WV.TEK.COM>
Date: 13 Nov 89 20:16:33 GMT
References: <89313.093518ALE101@PSUVM.BITNET>
Reply-To: kevind@pogo.WV.TEK.COM (Kevin Draz)
Organization: Tektronix, Inc., Wilsonville,  OR.
Lines: 39
Followup-To:comp.sys.mac

In regards to Soft-PC, by Insignia Solutions:

I purchased a copy when I worked at an Apple dealer, and run on my Mac IIcx.
I have found that it does indeed run every PC app I throw at it.  Especially
"Leisure Suit Larry in the Land of the Lounge Lizards."   It gives CGA
emulation, and Norton reports it is actually slightly FASTER than the
original XT, and it's hard disk performance is 20x faster. 

And yes, no hardware mods are necessary - it will even run in the background
under MultiFinder.  It is very memory hungry, however.  It likes 4MB or
more, but will run with a minimum of 2.

It emulates the 8088 processor in software.  Not really so difficult, as a
4.77 MHZ, 8 bit chip is not too hard for a 16 MHZ, 32 bit CPU to
"interpret".  This gives you a very crude estimate of 7-8 times the MIPS of
the slower machine.  Using a look-up table approach to opcodes, you would
only have 8 CPU instructions (again very crude way to measure, the
instructions execute in tremendously various numbers of clock cycles.) to
execute one emulated opcode - not so bad.

With some "filtering" for hardware mapped I/O and memory addresses, you
trap on accesses to these addresses, and duplicate the expected hardware
result.  

A hard disk is mapped to a user-selectable sized "virtual" hard disk, which
appears as a normal macintosh file.  You can install a C: and a D:.  An
apple 5.25" drive, or the FDHD can be used as drive A:.  An optional drive
E: can be created, which acts as a network drive and actually accesses
Macintosh files.

I find the product to be useful, as well as amusing, and well worth the $200
price tag.

(Now, will someone do such a good job for a IIe/IIgs emulator? )

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kevind@pogo.wv.tek.com
Tektronix Color Printers Technical Support