From: rmk@rmkhome.UUCP (Rick Kelly)
Organization: The Man With Ten Cats
Date: Sat, 19 Dec 1992 03:21:24 GMT
Reply-To: rmk@rmkhome.UUCP (Rick Kelly)
Keywords: apple, IBM, NeXTstep, NT, Kibo

In article <1gqe4nINNdq4@agate.berkeley.edu> nweaver@soda.berkeley.edu (Nicholas C. Weaver) writes:
>In article <9212162327.54@rmkhome.UUCP} rmk@rmkhome.UUCP (Rick Kelly) writes:
>}In article <1992Dec16.180320.13556@gallant.apple.com} cheryl@gallant.apple.com (Cheryl Lins) writes:
>}}In article <9212151730.20@rmkhome.UUCP} rmk@rmkhome.UUCP (Rick Kelly) writes:
>}}}There seems to be two "rumors" floating around.
>}}}
>}}}1. PowerOpen, which will run on the PowerPC, will be a base OS consisting
>}}}   of a mixture of AIX and A/UX, with a MacOS emulation and Multifinder
>}}}   running on top.
>}}}
>}}}2. Taligent, which will run on the PowerPC, will be released without any
>}}}   application compatibility to any other OS.
>}}}
>}}}Why would Apple base an OS on a processor chip that they no longer support
>}}}in their product line?
>}}
>}}If i were writing a _new_ OS, i'd agree that that would be a Dumb Idea. But
>}}there happens to be millions of existing Macs out there with lots of software.
>}
>}Well, that depends on how literally the emulate the 68020, and if it wouldn't
>}be better to emulate the 68030.
>
>	They don't really need to.  If I recall, the only real difference
>between the 020 and the 030 is the PMMU is built into the 030.  Motorola's
>chip designations are that even numbers are major increases, odd numbers are
>minor upgrades.  You don't hear about the 68010.  (Although the 68060 isn't
>as bing a leap over the 040 as the 040 was over the 030).  There may be
>other differences, but I don't thinky they will be too significant.

True, there are only slight differences between o20 and 030, and they
probably wouldn't affect an emulator.

The 68010 was the 68k family member that could do VM/demand paging.

>}}Now, do you want to know a _really_ Dumb Idea? Produce a new personal
>}}computer running a brand new computer chip and a new OS and don't have any
>}}application software to run on it at introduction (let alone thousands of
>}}software titles). Apple engineers are not that dumb. Even Apple managers aren't
>}}that dumb. :-)
>
>	It's not necessarily dumb.  Having a sub-feature that's backwards
>compatibility is nice these days, but is not required per-se.  Witness
>NeXTstep for an example, although they are going to have some sort of
>DOS/Windoz function on NeXTstep 486 (For those who bought the wrong computer
>in the first place, and are regretting their decision  :)

But then DOS emulation is available for SVR3 and SVR4.

>}Which machine is that?  Alpha?  Between OpenVMS and UNIX they have plenty of
>}apps.
>}
>}DEC is only planning to sell NT on one low-end model.
>}
>}}Some of us do have a clue, even if the rest of the world hasn't figured that
>}}out yet.
>}
>}When the Mac ships with a real command line shell, then maybe some people
>}will look on it more favorably.
>
>	They do, it's called A/UX.  And it is something that they seem to be
>letting languish at the sideline.  Apple today could release something that
>is 95% of what talegent promisses to be if instead, two years ago, they
>built something GOOD on A/UX, and started making it multi-platform.  Also
>make a decent development environment (C++ or Objective-C, a solid interface
>builder and debugger.  Hey, just hack GCC for the compiler).

The problem is that Apple hasn't put enough into the MacOS emulation for
A/UX.

>	The biggest uglyness that I see with NT and Taligent is the emulator
>approach.  Both promise to be multi-platform, but they both emulate a chip
>for cross computer work.  I think the fat binary concept (the application
>wrapper has binaries for all different computers, and just uses the one
>appropriate for the job.  Of course, make it strippable), works better
>because of the performance bottleneck from emulation.  This requires
>slightly more work for the developer.  (He has to go somewhere to compile on
>the other architectures, but that is simply the few hours it takes to
>compile soemthing), and a slight lag when a new architecture is announced
>for the OS, but the end user benefits from better performance.  Emulation
>should only be used for backwards compatability to a previous
>OS/architecture, such as System 6*/680x0 software for an Apple RISC machine,
>although it is better to just make cross compilation painless in the long
>run.
>
>	However, this does also complicate the job for the OS manufacturer,
>dependong on how much the manufacturer is relying on the emulation to run
>his GUI/OS if the manufacturer is going the emulation route.  

Microsoft is extremely in control of ports of NT.  There are very few
source licenses for NT out there.

-- 

Rick Kelly	rmk@rmkhome.UUCP	unixland!rmkhome!rmk	rmk@frog.UUCP
Newsgroups: alt.folklore.computers