How Do I Get That Rom?

In order for Basilisk II to run properly, it requires a Macintosh ROM image. On a real Macintosh, the information to run the computer is contained in a special chip, or set of chips, called ROM chips. Basilisk II needs the information from these ROM chips in order to function. This tutorial will outline the steps needed to extract the information from the Macintosh ROM, save it to a file on a floppy disk, and then transfer it over to Basilisk II. The steps outlined below require a Windows-based PC and a real 68k based Macintosh. The resulting ROM image can be used on all other ports of Basilisk II however, and is not limited to the Windows version.

Disclaimer (and Other Useful Info)…
First and foremost, the following tutorial cannot be used on a Macintosh system that you do not own. It is illegal to extract the ROM image from the Mac unless you actually own it. Second of all, this tutorial is not meant to cover PowerMacintosh systems. In its current build, Basilisk II will only emulate 68k based Macintoshes. These are the Macs that run on the Motorola 680×0 line of processors. Also, ROMs from especially old Macintoshes (such as the black and white Macs) will not work with Basilisk II. You are safe with Macintosh systems that use a 512k or 1mb ROM. These include most of the color Macintoshes (again, excluding the PowerMacs) such as the Mac II line and the Quadra models.

Before getting started, here’s a list of some utilities that you’ll need.

Phase One: Creating the Macintosh ROM Disk…
When downloading Basilisk II, a program called “GetROM” is included in the package. This special program allows you to extract the information from a real Macintosh’s ROM and save it to a file on the disk. Due to the way that the Macintosh stores information on disks, we need to get this program onto a Macintosh formatted disk in order for the program to work correctly.

  1. If you haven’t already done so, download the Macintosh disk image containing the GetROM application. The file is in ZIP format, and will need to be decompressed by using a utility such as WinZip (, and is about 124k in size.
  2. Put a blank floppy disk into your Windows PC’s drive, and launch HFV Explorer.
  3. Click the “Write Floppy” icon across the top of the screen, circled in red in Figure 1 below.
  4. A new screen will pop up. Make sure that the box next to “Floppy Drive” reads “A:“. In the “Volume File Path” field, make sure that the path points to the Macintosh disk image that you downloaded and decompressed in step 1 above. If need be, click the browse button (the button that has two greater-than symbols on it) to navigate to the disk image. The image should be called “get_rom.hfv“. In the example in Figure 2 below, the path to the filedisk is on the Windows Desktop (c:\windows\desktop\get_rom.hfv).
  5. Click “OK“. This will write the contents of the GetROM disk image to the floppy in your PC’s floppy drive, in Macintosh HFS Standard format.
  6. When the process is complete (it may take several minutes), you will see a warning message that states that you now have two volumes with the same name. First, eject the floppy from the PC’s drive. Then, click “OK” and exit HFV Explorer.

PearPC:Mac OS X

Addendum: Since I wrote this, I have been informed that there is indeed another PowerPC emulator out there called SheepShaver, and although it does not run Mac OS X, it does run Mac OS 8.6-9. Check it out here!

It has literally taken years. Years of broken promises from commercial vendors claiming to have been on the verge of releasing what has proven to be the impossible task of emulating, through software, the PowerPC architecture (Two big offenders are Microcode Solutions’ Fusion PowerPC and’s SoftMac Professional). So what happens when commercial vendors fail? Leave it to the resourceful folks at SourceForge to come up with an open source (and free) PowerPC emulator for both Linux and Windows. What does PearPC do? Here’s some highlights:

  • PowerPC G3 processor emulation
  • Ethernet networking
  • The ability to run multiple PowerPC-based operating systems

However, there are some limitations to what PearPC can do:

  • The PowerPC emulation does not support the vector processing technology of AltiVec (a.k.a., Apple’s “Velocity Engine”). AltiVec is roughly akin to Intel’s MMX technology (Note: there are experimental builds of PearPC that do dabble into AltiVec; check this link for more information).
  • PearPC has no sound support
  • PearPC does not support USB, although it “fakes” USB well enough to fool the operating system running within it
  • The emulation is, well, slow

I know that this last point is a real killer, but it’s a fact. The truth of the matter is that it is much more difficult for a CISC (Complex Instruction Set Computer) chip such as a Pentium IV to emulate a RISC (Reduced Instruction Set Computing) chip, such as the PowerPC, than for a RISC chip to emulate CISC.

So how slow is it? That depends on the version of PearPC that you run. There are currently two flavors: a generic and a JIT (Just In Time) version. The generic version is the slowest, running about 400 times slower than the computer on which PearPC runs (Yes…you read that correctly). So, if you have a 400Mhz Pentium, the generic PearPC version should top out at a screaming 1Mhz on your system. Fortunately, there is hope. The JIT version of PearPC is a bit more efficient, running at a much faster pace of 40 times slower than the host hardware. This means that our 400Mhz Pentium would drive PearPC at about 10Mhz. In a real world scenario, this would put PearPC at about 77Mhz on a 3GHz Pentium. And although this may be a bit depressing, the fact that we actually have a PowerPC emulation environment running in a completely alien computing architecture is well, quite cool.

I am writing several tutorials on PearPC, dealing mainly with the Windows platform emulating Mac OS X systems. At this time, the tutorials encompass the following:

So sit back, relax, and enjoy the PearPC experience!

Questions? Feel free to contact me at

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Install OS X on Pear PC

Accessing Mac OS X 10.3 Installer CDs from PearPC…

Buy a Copy of Mac OS X 10.3
Use MacDrive to Access Installer CDs
Use UltraISO to Create Disk Images

Installation Preparation…

Before we can install Mac OS X, we need something onto which we can install it. Normally, this is a Macintosh formatted hard drive. But PearPC does not use a physical hard drive. Just as it uses ISO disc images instead of real CDs, it uses hard disk images. A hard disk image is a file that contains what the emulated Macintosh thinks is a real, physical hard disk. PearPC also requires some other “tweaks” in order to create a working, bootable Mac OS X configuration. (Fortunately, I have done that work for you, which should save you a good 500mb in downloads).

Your download list for this portion of the tutorial looks like this:

The hard disk image file prepared for a Mac OS X installation (about 6mb in size). This file is a self-extracting, compressed archive. Double-click it to extract it. Allow yourself some time and some hard disk space, as this image file decompresses from 6MB to 6GB.
The most recent version of PearPC (currently at version .31) for Windows, or Win32. I highly recommend the JIT version of the software

The Installation Process…

1. Create a folder on your C hard drive and name it PearPC. Unpack all the software that you downloaded above and place everything in this new directory.

2. Copy the OSX3.iso image that we created in the previous tutorial to the PearPC directory. This should leave you with three items in the PearPC directory: the main program directory (i.e., pearpc-0.3.1-win32-jitc) the hard disk image 6gb.img, and the OSX3.iso disc image. Copy the entire contents of the pearpc-0.3.1-win32.jitc to the PearPC directory that we created in step 1. Once you’ve verified that pearpc-0.3.1-win32.jitc is empty, delete it.

3. In the PearPC directory, locate the file named pearpc.example and open it with WordPad.

PearPC is driven by what it finds in this configuration file. Most of the items in this file are fine if left alone. However, we need to tell PearPC where to find both the OSX3.iso and 6gb.img disk images, and in what order to boot.

4. In WordPad, scroll through the text file until you come to the line labeled prom_bootmethod. The default value for this setting is auto. Change this value to select as is shown here:

prom_bootmethod = “select”

5. Continue scrolling through the textfile until you find the line labeled pci_ide0_master_image = “/test/imgs/linux.img”. This line tells PearPC where to find its hard disk image file. Edit this line to read like the following:

pci_ide0_master_image = “c:\pearpc\6gb.img”

6. Edit the line that reads pci_ide0_slave_image = “/dev/cdrom” to read like the following:

pci_ide0_slave_image = “c:\pearpc\osx3.iso”

7. Click File and Save As. Give this file a name of OSX.pearpc.

8. Open a command prompt by clicking Start->Run and entering the text cmd or command. Type CD c:\pearpc and hit enter. PearPC’s syntax is very simple: pearpc . For our example here, we type the following, and hit enter:

ppc osx.pearpc

9. PearPC launches (at last!). It presents you with a list of boot options. We wish to boot from the ISO disc image containing the Mac OS X installation material. In this case, we see that this is option 1. Press 1, and hit enter:

The Mac OS X installation boots (and boots very slowly; don’t get too impatient, as the install screen will eventually come up).

10. The Mac OS X 10.3 installation screen appears, asking for you to choose a language in which to install Mac OS X. Select your language of choice and click Continue. A welcome screen appears.Click Continue. Click Continue two more times, and Agree with the license agreement.

11. The installer asks for a location in which to install Mac OS X. Click the disk named PearPC and choose Continue:

12. Since we wish to perform a customized installation of Mac OS X, click the Customize button in the lower left of the installer window. Remove the checks from the items labeled Additional Applications, Printer Drivers, Additional Speech Voices, Fonts, and Language Translations. Click Install.

13. When the installation attempts to run a check on the installation disc, click Skip in the lower right corner of the screen.

You should now acquint yourself with a good book or a nice, long movie. Installation of Mac OS X can take hours. On a 2GHz Pentium 4 system, this basic installation tops out at about three hours.

15. Once the installation process completes, PearPC quits abruptly. This is normal. To finish things up, edit the macosx.pearpc once again, place a “0” after the line PearPC about the existance of a CD-ROM:

pci_ide0_slave_installed = 0

This tells PearPC that our CD-ROM is no longer installed. Now boot PearPC in the same way as in step 8 above, choosing 1 to boot PearPC into Mac OS X. Congratulations – you are now running Mac OS X on a Windows computer! (Note: when the Mac OS X Setup Assistant asks you for information on connecting to the internet, tell it that you are not ready to connect at this time).

Creating ISO CD disc images from Mac OS X installer CDs.
Installing Mac OS X
Configuring Mac OS X networking
PC/Mac File Sharing
Printing From PearPC
Integrating PearPC and Active Directory

Questions? Feel free to contact me at

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