MARKS-ROGER@YALE.ARPA (12/18/86)
>Great News!!!! >In Europe people succeeded in writing a *software* Mac Emulator. Which >basically works the same as the hardware Magic Sac, but instead of needing >a set of Macintosh Roms in the cartridge port, it loads the Rom contents >into _memory_. >The good thing of all this is that the software emulator may be Public >Domain! Ofcourse, it does not include the Mac Rom contents themselves. You >will probably be requested to buy them and transfer them to disk. I'm confused. It seems to me that one should consider ROMs to be hardware. Debate this if you'd like, but the fact remains that I can't imagine being able to "transfer" the ROMs to disk without some sort of...hardware. The Sac solution of plugging the ROMs into the cartridge port seems to me eminently reasonable. And, of course, the Sac is part software too. Why do I make an issue over this? Read on... >I'm inclined to believe that ....(the inventor of the Magic Sac) >just made a hardware version in order to boost his profits. Obviously, >this works just as fine. I find this statement outrageously offensive. From my vantage point, the Sac seems like a perfectly rational design. If someone has something better or cheaper to offer, fantastic. But to come out with a vicious remark, based entirely on the author's imagination and without any apparent purpose, is pure sleazeville. While I'm at it, a certain guy at Atari has been taking a lot of cheap shots on this net from people who expect continuous attention from him just because they know his name. Complain about his employer if you have to, but keep the personal stuff out of it. This isn't just my cockamamy notion-- check the net ground rules. While I'll admit that I wouldn't be flaming away if I didn't perceive the people in question to be two of the "nice guys", I think the principle is more general than that. The principle is, come on, guys, let's be civilized. FYI: I have no connection with any of the parties involved. Roger Marks@yale.arpa -------
grunau_b@husc4.harvard.edu (justin grunau) (12/19/86)
I agree 100% with MARKS-ROGER@YALE.ARPA on his response to Patrick@ark
(Paul Molenaar?) regarding the Magic Sac and this alleged "new European
emulator". It was offensive to imply that David Small is trying to boost
his profits by using hardware instead of software; it is, however, probably
based on a gross misunderstanding.
In no rational sense can David Small's cartridge be called a "hardware
emulator". The cartridge itself does not contain any of the emulation ware
at all -- the emulation, if you can call it that, is done by software that
you get on a little TOS diskette.
A good example of a hardware emulator is Atari's upcoming Big Blue Box: they
use hardware (an 8088, amongst many other things) to convince the MS-DOS
software that it is running on an MS-DOS machine. The better the emulator,
the closer the software actually IS to running on an MS-DOS machine: the
MacCharlie emulator is supposed to be an IBM clone without the keyboard and
screen.
A good example of a software emulator is Paradox's MS.EM. -- it is software that
runs on the 68000 that emulates the hardware activities that an 8088 would
perform: in other words, it is just an 808X instruction set interpreter, no
different in principle from a BASIC interpreter. I think we can rule this
definition of software emulation out for the European Mac emulator: it would
be foolish (and very slow) to write a 68000 interpreter that would run on a
68000.
In any event, the Magic Sac is neither version of emulator, least of all a
hardware emulator, because you have the most relevant piece of hardware there
already: the 68000! The only emulation ware he sells you is his set of
patches to the MacIntosh OS that re-route hardware references to the ST
hardware, which is of course quite different from the Mac's. Any software
that bypasses calls to the OS and directly references hardware will of course
fail miserably on the Magic Sac, and unfortunately more applications do that
than we would like. The ROM cartridge isn't really "hardware emulation" --
it's just a legal way to get the SOFTWARE contained in the Apple ROMs into
your machine. Copying the contents of the ROMs onto disk and selling them would
be highly illegal, and I doubt the Europeans are doing that. Also, it is hard
to see an advantage to loading the ROM software into your RAM -- if you use the
cartridge, you don't use up any RAM, which is a clear advantage!
Now that we have cleared this up, perhaps the original note writer would like
to elaborate on his report, and/or direct us to the original sources? I would
speculate that if the European approach is truly different, it must be a
rewrite of the Apple ROMs (a la Phoenix's version of the IBM BIOS). It is
hard to see offhand how this would be any better than using the real ROMs --
here, too, I would expect that applications which directly access hardware
would fail, and I don't think it would be cheaper to develop such a product
than what David Small has done ...
JJMG
{ seismo OR rutgers OR decvax!ihnp4 } !husc6!husc4!grunau_bmugc@utecfb.Toronto.Edu (ModemUserGroupChairman) (12/20/86)
In article <8612181103.AA02378@ucbvax.Berkeley.EDU> <MARKS-ROGER@YALE.ARPA> writes: [in reply to a rude sounding announcement about a mac emulator] > I find this statement outrageously offensive. From my vantage point, >the Sac seems like a perfectly rational design. > ... > While I'm at it, a certain guy at Atari has been taking a lot of >cheap shots on this net from people who expect continuous attention from him >just because they know his name. Complain about his employer if you have to, >but keep the personal stuff out of it... I whole heartedly agree. Getting personal is very low indeed, but when it is done in public (in front of the whole world so to speak!) it's truly rotten. >Roger >Marks@yale.arpa >------- anees munshi