[rescue] Mac Hints needed

Geoffrey S. Mendelson gsm at mendelson.com
Tue Nov 4 01:51:50 CST 2003

James Birdsall wrote:
> A genuine question: why did Apple go to so much trouble to make sure that
> Macs can't boot anything but MacOS?

They did not. For example, while they did have a proprietery boot
system, they replaced it with a clone of Sun's "Open Boot" in the later

The reason that the "alternative" operating systems, boot from MacOS and
not native on the older Macs, was that once it was set up that way no
one wanted to spend the time and effort to make a native bootloader.

AFIK except for possibly a short time in the CHRP days, an APPLE
computer came with MacOS. It wasn't an option, one could not be
purchased without the other. I'm not even sure that you could buy a
APPLE CHRP without MacOS.

I know that the new Macs are CHRPS, or very close to them, but APPLE is
not interested in promoting them as such, nor or the other players still
offering COMMERCIAL CHRP operating systems, e.g. Sun and Microsoft.

I don't know about AIX, is it still available for APPLE computers? Will
it run on a G5?

> protection for the software. MacOS wasn't copy-protected at all, so that's

The MacOS awas copy protected in a very simple way. It required the
toolbox in the ROM to work. In reality, you only got half of the operating
system on disk. 

The loadable part of the system did include ROM patches, for example the
upgrade from the original 64k roms (no folders on disks) to the 128k
ROMS, support for SCSI, etc. 

When System 7 came out and there was a wide need for more than 16m of ram,
a third party product that patched the ROMs to make them "32 bit" clean,
was purchased by Apple and distributed for free. This made older machines
more usefull as even at $50/meg add ram cheaply compared to the cost of
the computers themselves.

Then Apple got the idea that they could include 3rd party software and
SELL the operating system. System 7.1 to this day is not free, as Apple
has to pay royalties on each copy sold.

Whatever it was, the code was removed in System 7.5, which was not free,
but has since be released to anyone that wants it. If you nose around,
you can find the "System" as it was called from its earliest release
up to 7.0.1 free for download from Apple and 7.5, 7.5.3, 7.5.5, but
not 7.1.

7.6 and  8.0 was also sold and is still for sale, but it may be hard to
find. 8.1 was a free upgrade to 8.0, but I have an 8.1 CD for the first
G3, as it won't boot 8.0.

I think the first CHRP release was 8.5 as it is PPC only and does not
require an Apple ROM. The ROM image is included on the CD and loaded
at boot time. 8.6 (a fix to 8.5) and 9.0 and 9.1 also included the
ROM image. 9.2 does too, but it will not run on a real machine, only
in a window of MacOS X (ten).

MacOS 10.0, 10.1 and 10.2 woudl boot on a "old world" (not Open Boot)
Mac, but do not require the ROM image at all. The BSD operating system
does not use it at all, nor does the GUI. 

Rumor has it that Apple produces a version of MacOS X, called "marklar"
which runs on current Intel hardware, but it is not available to the

The latest MacOS X (10.3) will not boot on a Mac without Open Boot, but
there is a third party program that runs under MacOS 9 that will boot it.


Geoffrey S. Mendelson gsm at mendelson.com 972-54-608-069
Icq/AIM Uin: 2661079 MSN IM: geoffrey_mendelson at hotmail.com (Not for email)
Carp are bottom feeders, koi are too, and not surprisingly are ferrets.

More information about the rescue mailing list