Brings Classic Mac OS to Intel Macs and Leopard
by Alan Zisman (c)
published in Low
21 May 2008 Mac2Windows column
Early in 2006, I wrote an article for Low End Mac entitled VNC,
Basilisk II, and SheepShaver: 3 Ways to Run Classic on an Intel Mac
In it, I noted that the then-new Intel-powered Macs were unable to run
older Mac software in called Classic Mode, but that there were at least
a couple of ways to get around that, including Basilisk II, which
emulates old 680x0 Macs, and SheepShaver, which emulates newer pre-OS X
While SheepShaver, promising emulation of Macs
from the late 1990s, would seem a better solution than Basilisk -
emulating Macs from the 1980s through early 1990s - I noted in that
article: "I've been trying to make (SheepShaver) work . . . So far, all
I get is a black window."
While many of us no longer rely on old
Classic mode software, Apple gives Classic mode even less support than
at the time I wrote that article. At that time, if you had a PowerPC
Mac, you could still run older software in Classic Mode if needed. But
now, if you've upgraded to Mac OS X 10.5 Leopard, your PowerPC Mac will
also be Classic-less.
I recently bought a secondhand 12" G4
PowerBook (more on that another time); it came with Mac OS X
10.4 installed, but I upgraded it to 10.5, thus nuking its Classic Mode
capabilities. So I thought it might be time to give SheepShaver another
is an open source project designed to emulate Power Mac hardware with
versions for Mac OS X, Linux, Windows, and more. In order to make
it work, you need to download a copy appropriate for your hardware and
operating system, have handy a copy of the Mac operating system
(versions 7.5.2 through 9.0.4 - and not a copy that's tied to a
specific piece of hardware), and access to a Mac ROM image. You need
the ROM image in order to allow your emulated Mac to start the boot
process - where standard Windows-style PCs have fairly simple ROM
BIOSes, PowerPC Macs need access to a hunk of Apple-written (and Apple
copyright) code before they start to load the operating system.
Mac ROM image is the catch. If you have access to a PowerPC Mac from
that late 1990s era, you could, presumably, make an image using the ROM
Grabber utility. But you may want to emulate a PowerPC Mac because you
don't have access to an actual running computer of that era.
the firmware updater file included in the Mac OS 8.5 or 8.6 CD (in the
System Folder) is supposed to be usable as a ROM image. It didn't work
for me - all I got was a black screen when I tried to start up
SheepShaver. Apple has a Mac OS ROM Update
available online that is also supposed to be usable in this way, but
you need to be able to extract the ROM image from the software
installer. The recommended way is to use a utility called TomeViewer
But TomeViewer is a Classic Mode program - if all you've got is an
Intel Mac or a PowerPC Mac with Leopard (which is my situation), you
can't make it work. After all, running Classic Mode programs is what
this is all about!
A hunt online got me a number of dead ends but
eventually led me to
"New World PPC ROM". I unzipped it, pointed SheepShaver to it, and was
well on my way.
Setting Up SheepShaver
SheepShaver stores its
critical settings in a text configuration file, but the Mac version
includes a graphical front end that simplifies configuring it without
having to ever touch a text editor. You'll find it in your SheepShaver
application folder, under the name SheepShaverGUI. It looks like an old
Unix Motif-style application, rather than something designed for a Mac,
but it's pretty straightforward.
your virtual hard driveFirst, create a 'volume', a disk image, where
you'll be installing the classic Mac OS of your choice, by looking on
the Volumes tab, and clicking the Create... button. I put mine in my
Documents folder, so I scrolled down the Unix-style Directors list on
the left to find Users, double-clicked to open it, found my name,
opened it, scrolled down the list to find the Documents folder.
gave it a size of 512 MB, and in the Selection box, gave it a name.
When I clicked OK, nothing much seemed to happen for a moment or two,
but after that, I had a 512 MB file with the proper name in my
Back to the Volumes settings tab. It showed my
newly created virtual hard drive. The next setting, Unix Root, may seem
obscure. In both Basilisk II and SheepShaver, when booted, the desktop
shows at least two drive icons: one for the Mac boot drive, which we
just created, and another one labeled Unix. Double-clicking it shows
the contents of your 'real' Mac's drive. With the root setting, you're
able to set how much of the Mac drive to make available - the default /
makes the entire drive available; you might prefer to start with your
Home folder (for instance, /Users/azisman in my case).
you can set to boot from 'Any' or 'CD-ROM'. If installing from a Mac OS
CD, the latter might be the best choice - at least for your first boot.
Finally, you have an option to disable the CD-ROM driver. We'll see
later that this might be a good choice for day-to-day operation.
The Graphics/Sound tab lets you set the screen size; I
picked 800 x
600. As well, you can enable or disable sound output. Sound works, but
there may be a trick needed, which I'll tell you about in a moment.
I didn't need to do anything to the default settings
Keyboard/Mouse tab. The Serial/Network tab is worth a quick peek -
setting the Ethernet Interface option to 'slirp' let me get online
using my Macs default networking setting - yes, it worked with both
wired ethernet and an AirPort connection on the Mac.
Memory/Misc tab has two important settings. In the first, you need to
set how much RAM to give your virtual Mac when it's running. Your
decision should depend on how much RAM is installed on your 'real' Mac;
you don't want to give the virtual Mac so much RAM that you starve
OS X. But remember, Macs from that late 1990s-era didn't have much
RAM, at least by contemporary standards. I bought a G3 iMac in 1999,
for instance, that came with either 32 or 64 MB (I forget - in either
case, not very much). I gave my virtual Mac 128 MB; a large amount for
a Mac of that era, but not so much that it will cause problems on my
real Mac. (In any case, the real Mac gets the RAM back when SheepShaver
Finally, in that tab, you need to point to the
location of your ROM
image file. I copied mine into my SheepShaver application folder. I
ignored the JIT Compiler folder.
When the SheepShaver GUI settings look okay, you can
click its Start
button in the lower-left corner. Alternatively, double-clicking the
SheepShaver application file will just start it up, without giving you
access to all those configuration settings.
Before starting SheepShaver for the first time, I
inserted my OS 8.5
CD and set SheepShaver to boot from the CD. The CD installation program
started up, but first it initialized my newly created virtual hard
drive file, treating it just like a real Mac hard drive. Following
that, I was able to install Mac OS 8.5 without problem, and (after
resetting the configuration option to boot to 'any') was able to boot
up to the 'hard drive' of my new 1998-era Mac.
I copied the SheepShaver application and virtual hard
over from my PowerBook to my Intel iMac, so now I have two of them.
Copying over was straightforward, though the copied-over ROM image
didn't work, so I downloaded another one.
When starting up for the first time, Mac OS 8.5 tried
to run a
network setup routine. It seemed to be taking a long time to recognize
the networking hardware, so I canceled it. After that, a little
fiddling with the TCP/IP control panel was all it took to make Internet
access happen. It seems happy just setting up for DHCP and leaving
everything else blank.
At first, there was no sound. It turns out that with
Mac OS 8.5/8.6,
the Monitors & Sound control panel isn't the one you need to use -
instead, look for the old Sound control panel, located in the \Apple
Extras\Sound Control Panel folder; set Sound Out to Built-in, and
you're in business.
One more thing to avoid: OS 8.5/8.6 has a nice
panel. The Sound tab offers a 'Platinum' sound track. Choosing it
immediately crashed my virtual Macs.
One more problem: CDs were accessible without problem,
CD was inserted into the Mac prior to starting SheepShaver or
afterwards. But ejecting them was problematic. The 'real' Mac wouldn't
eject them, because they were still in use in SheepShaver. But ejecting
them in SheepShaver just got me a spinning wheel. Better to shut down
the virtual Mac, then eject the disc.
Inserting a USB memory stick did not get me an icon on
SheepShaver screen - but I could copy data from the memory stick to a
location on my (real) Mac's hard drive, then access that using the
virtual Mac's Unix drive icon.
Performance on my Intel iMac is pretty good, but
performance on my
older (PowerPC) 12" PowerBook is spectacular - far and away the fastest
classic Mac I've ever used. That's because on an Intel Mac, SheepShaver
has to emulate PowerPC instructions, translating them into Intel code;
on a PowerPC Mac, no translation is necessary. As an example, it takes
about 45 seconds to boot the virtual Mac on my 2 GHz Intel iMac.
On my 1.5 GHz G4 PowerBook, the same thing takes 16 seconds. That makes
it way faster than it used to take to start up Classic Mode!
Frankly, I don't have much use for Classic Mode; I no
on any of those older programs. But if you do, and you're worried about
not being able to run them after getting a new Mac or upgrading an
older one to Leopard, SheepShaver may be your answer.
Or maybe it's just fun to play with.
November 30 2008: Reader Steven B. asked "Can't figure out how to make
a virtual HD. I have never worked with Unix Motif-style application. I
must be missing something.
Do I somehow make the virtual Disk in OS 10 BEFORE I follow the
1) Open the SheepShaverGUI application. With the
Volumes tab showing, click the Create button.
In the field on the left, scroll down the Directories list-- this will
show a bunch of folders that are usually hidden in Mac OS X; if you
want to create a new virtual hard drive within your Documents folder,
double-click on the Users folder. That will show your user name-
Double-click on that and you'll see your Documents folder...
Double-click to open that.
In the Size field, type a size for the virtual hard drive (in MB) or
accept the default 40 MB.
In the bottom field (Selection: /blahblah) type a name for the file
that is being created.
OK-- you should see the 'spinning wheel' for a moment, then your new
drive will appear in the drives list in the Volumes tab.
Note that it still needs to be initialized (formatted), whether from a
Mac OS installation CD, or in my case from my installed copy of Mac OS.
Steve, however, went 'another route':
went into OS10 disk utility and created an "image", which I named. I
followed the rest of the instructions and used the ROM you provided the
Started up SheepSaver with my OS 9.0 disk in the drive
and everything came up such that I was able to select the "image" as
the destination disk and load OS9.0.
Got tricky to load an
application. Returned to OS 10, opened the new "image with OS 9 on it"
and dragged/dropped the application (Strategic Conquest).
Restarted SheepSaver and there was my app. Been playing ever since!"
The moral: there's more than one way to shave a sheep!