VNC, Basilisk II, and SheepShaver: 3 Ways to Run Classic on an Intel Mac

- 2006.02.20 - Tip Jar

We're in the middle of yet another of Apple's big transitions.

In the first half of the 1990s, there was the transition from the Mac's original 680x0 family of CPUs to the PowerPC chips. In the early 2000s, there was a transition from the classic line of Mac operating systems to the Unix-derived OS X family. And now Apple has released the first models powered by Intel CPUs, with promises that the whole product-line will be Intel-powered by the end of 2006.

While each transition has ultimately been good for users, each time there's been a rough period as software had to catch up with the new hardware. Early adopters of PowerPC-based Macs had to run software designed for the earlier models; it would run on the Power Macs, but at nothing like the speed those models were capable of.

If OS X users need to run software designed for pre-OS X Mac operating systems, they can launch Classic-mode; a window running Mac OS 9.2.x on their OS X desktop. It's a bit awkward, but it works - at least most of the time.

Owners of the new Intel-powered Macs are hit with a double whammy. OS X had to be rewritten to run on this very different processor family, and to get best performance applications also need to be recompiled (and in some cases completely rewritten) to support the new hardware and operating system version.

OS X software compiled for PowerPC processors will run on the Intel Macs, using a translation layer called Rosetta. But Rosetta's on-the-fly translations sap computer performance. Those applications run noticeably slower than on comparable previous-generation Macs.

Mac OS 9 isn't usable at all on the new hardware, so users who still rely on old Classic mode applications are simply out of luck if, lured by promises of double or triple the performance, they purchase a new Intel-powered Mac.

Or are they?

There are a couple of ways to make an end run around the Intel Macs' lack of Classic mode support. For instance, if users still have their previous Mac around (or if they buy a low-cost Mac like a mini), they could simply keep using it when they need access to that old Classic mode application.

VNC: The Hardware Solution

Somewhat more high tech would be to keep that PowerPC Mac up and running, then access it from the Intel Mac using a remote desktop application like the open source VNC (Virtual Network Computing). A wide range of versions of VNC are available for a wide range of computing platforms, including both OS X and OS 9.

Running a VNC server on the old Mac (running either OS X or even OS 9) and a VNC client on the new Intel Mac with both connected on a TCP/IP network would let a user sitting at the new Mac open up a window to the old one and run the Classic application remotely.

Emulation: The Software Solution

I'm taking a different course, however. Instead, I'm trying out emulators. Here's why:

I have a teacher colleague who just replaced his Windows PC with a brand new Intel iMac. Everything's fine, except that elementary teachers in our school district often use a program called Silhouette for generating report cards. Duet Software has produced a Windows version and a Classic OS Mac version. Since the Classic OS version runs fine under OS X Classic mode, they haven't created a native OS X version.

When I queried them, the two teachers who are Duet Software in their spare time said that it would require a complete rewrite to produce an OS X version, and with rumours that the school district will be moving to other software within the next year or so, it's not high on their to-do list.

Why not emulate Windows?

So those teachers with new Intel Macs who need Silhouette would seem to be out of luck. Current versions of Windows emulators - Virtual PC and Guest PC (see Guest PC: A More Affordable Way to Put Windows on Your Mac) - won't run on Intel Macs. Another emulator, iEmulator is promising an Intel-capable version soon, while OpenOSX WinTel claims its emulator already runs on the Intel hardware.

I'm waiting for the promised version of iEmulator and have spent a lot of time working with various versions of OpenOSX WinTel without having gotten to a point where I feel comfortable recommending it as a solution.

Instead, I'm looking using emulation to put an older Mac in a window on my colleague's Intel iMac.

Emulate a 680x0 Mac

I've previously written about Basilisk II, an open source emulator that puts a 680x0 Mac in a window on a Windows (or other operating system) desktop (see Mac Emulation With Basilisk II, vMac and Basilisk II Puts a Mac on a Windows Computer). Since those 2002 articles, a version of Basilisk II has been released that lets it run under Mac OS X as well. I've tried this on my PowerPC Mac, and it works - though I haven't been able to get the networking functional, something that works fine on the Windows version, in my experience.

(It may be just me - any reader who is able to get the Mac version's networking into gear should please drop me a line!)

It's kind of cool. But since my PPC Mac has Classic mode, I don't have much need to run a 680x0 Mac in a Window on my G5 iMac. (Your needs may differ. If you have old software that won't run under OS 9 or won't run at all in OS X's Classic mode, maybe this will let you continue to be productive).

I was pessimistic about running Basilisk II on an Intel Mac, however. After all, the various Windows emulators don't seem to run with the Intel Mac's Rosetta translation. They require extensive rewriting.

So I was pleasantly surprised when I copied the Basilisk II folder from my PPC iMac to my colleague's Intel iMac and discovered that it just worked!

There it was, a 68040-powered Mac Performa running Mac OS 7.6 in a window on an Intel iMac. A nice touch in Basilisk II is that it puts a "Unix" icon on the desktop, allowing easy transfer of files between the emulated Mac and its host system. That will be a big help in getting report card files out to the world.

Basilisk II Setup

In order to make Basilisk II work, you need three things:

• The Basilisk II application. Since it's open source, it can be downloaded freely
• A copy of an older Mac operating system. Apple has made operating system versions up to System 7.5.5 freely downloadable. You can find links for a wide range of older Mac operating system versions on Low End Mac's Classic Mac OS Downloads and Updates page. Apple included 680x0 support in operating system versions up to Mac OS 8.1, so that's the last version that Basilisk II can run.
• An image file of the ROM from a 680x0 Mac. In general, you'll get best performance from a more recent 68040 model. Apple retains copyright on their ROM code, so you can't legally download these (and I won't send my copies out, so please don't email me). Instead, if you find a working older Mac, you can "capture" a ROM image (see Capturing a Mac ROM Image)

You can find more details on getting set up with Basilisk II on 68k Classic Mac Gaming on OS X Using Basilisk.

While it works, Basilisk II is limited to emulating 680x0 Macs; in effect, models up to about 1994.

Emulate a PowerPC

Another open source project, SheepShaver, promises PowerPC emulation, in theory allowing emulation of hardware up to the 1998 beige G3s with operating systems up to Mac OS 9.0. The project has recently announced what they describe as an "experimental" port to Mac OS X for Intel.

Like Basilisk II, SheepShaver requires a Mac ROM image. In some ways, however, it may be easier to get the required ROM. According to Gwenole Beauchesne's SheepShaver Wiki, the so-called New World ROM image files included on Mac OS 8.5 and 8.6 CDs should be usable. Alternatively, a ROM Grabber utility can be used to make an image from the ROMs on any of a wide range of Power Macs.

SheepShaver has borrowed a number of features,including CD-ROM and ethernet support, from Basilisk II, updating them to run on (emulated) newer hardware. At least so I've heard.

I've been trying to make it work with the ROM file from a Mac OS 8.5 CD. So far, all I get is a black window.

I'll keep you informed - and again, if any of you are having any better luck with SheepShaver, please let me know!

For now, with Basilisk II running happily on the Intel iMac, my teacher colleague is able to get the Classic support he needs - as long as he's prepared to use software that will run on vintage Mac hardware and operating system versions.

In other words, putting a low-end Mac on a new Mac.

Works for me! 

• Link: VNC
• Link: Basilisk II
• Link: Basilisk II for OS X
• Link: Classic Mac OS Downloads and Updates
• Link: Capturing a Mac ROM Image
• Link: 68k Classic Mac Gaming on OS X Using Basilisk
• Link: SheepShaver
• Link: Gwenole Beauchesne's SheepShaver Wiki
• Link: ROM Grabber Utility