How Do I Get that Macintosh ROM into Basilisk II?

Tutorial by Marc Hoffman

Introduction...
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 680x0 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.

- A real 68k Macintosh, that you own. This does not include the computer at work or at school :-)
- HFV Explorer, a utility that allows Macintosh disks and file disks to be read on Windows and UNIX.
- A Mac-formatted disk that contains the "GetROM" utility. I have a disk image that we will use to create such a disk here.

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 (http://www.winzip.com/), 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.

Figure 1: The Write Image to Floppy Disk Icon

Figure 2: Write the Disk Image to a Mac Formatted Disk

Phase Two: Getting the ROM From Your Mac...
You now have the GetROM program on a Macintosh disk, in Macintosh format. You're ready to run it on a real Macintosh. This phase of the tutorial will cover the process of extracting the real ROM image from the Mac.

1. Boot your Macintosh as you normally would.
2. Place the GetROM disk in the Mac's floppy drive.
3. Several windows should open. Locate the program named "GetRom", and double-click it. This will extract the information from the Macintosh's ROM and save it to the floppy disk. When the process is complete, you will see a newly created file called "ROM". This is circled in red in Figure 3 below.
4. Eject the floppy from your Mac's drive (by dragging the floppy disk icon to the Mac's trash can). You now have the ROM image on a floppy disk.

Figure 3: The Newly Created ROM Image File

Phase Three: Copying the ROM File to the PC's Drive...
In order to get that newly created ROM file to the Windows hard drive, we need to go back into HFV Explorer and copy that image from the Mac floppy disk to the PC's drive.

1. Put the GetRom disk in the PC's floppy drive, and launch HFV Explorer.
2. When HFV Explorer is finished loading, click on the "A:\" drive on the left hand pane.
3. The contents of the Macintosh floppy disk will appear on the right hand pane. Locate the "ROM" file, and drag it to your PC's hard disk. This step is shown in Figure 4 below.
4. A new window will pop up, asking you to select the copy mode. From the drop down list, select "Raw Copy, Data Fork". This will copy the Macintosh's ROM file to the PC's hard disk. This step is shown in Figure 5 below.

Figure 4: Copy the ROM File to the PC's Drive

Figure 5: Select "Raw Copy, Data Fork"

Phase Three: Cleaning Up...
Now that you have the Macintosh's ROM on your hard disk C:\ drive, you can transfer it to anywhere you need to. The most obvious place to copy it to is the Basilisk II directory. You can always copy it to a PC formatted floppy and use this disk to transfer the ROM image to your Linux or Amiga system. Some examples on how to tell Basilisk II where to find the ROM file are shown below in Figures 6a and 6b. In 6a (which shows the Linux version of Basilisk II), the ROM is placed in the /home/marcrh/b2 directory. In Figure 6b, the ROM file is placed in the c:\basiliskII directory. This, of course, will vary on your system depending on where you plan to copy the ROM image to.

Figure 6a Top: The ROM Path in the Linux Version of Basilisk II

Figure 6b Bottom: The ROM Path in the Windows version of Basilisk II

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