How to use the Basilisk II System 7 emulator on macOS

The Basilisk II emulator can be used to run older versions of Mac OS 8 and System 7 on a modern Mac. Here's how to get started using it.

Before macOS and OS X there was Mac OS 9, and before that there were its predecessors: Mac OS 8 and System 7.x.

System 7 was released in 1991 and was the first version of Mac OS to feature color. Before this, the Mac was only black and white.

Early Mac computers used a Motorola processor called the 68000, better known simply as the 68K.

Emulate Mac OS 8 and System 7

Today, there are a number of emulators that you can run on your modern Mac to emulate Mac OS 8 and System 7 running on a vintage 68K Mac. Among them are Basilisk II, Sheepshaver, macintosh.js and others.

There are also many online Mac OS 9 emulators.

In this article we will look at the game Basilisk II, written by Christian Bauer.

Getting Basilisk II

To download Basilisk II, go to its page, which contains links to purchase the executable file. There is also a GitHub repository containing source code written in C++.

Please note that the download links are on the Basilisk II forums and can be a little confusing. The most recent message on the forum page at the time of this writing reads:

“SDL2 port, August 10, 2023, Universal (x86_64 and Arm64) from source code Universal, will run native on both Intel and Apple Silicon

Recommended for macOS 10.13 (High Sierra)–13 (Ventura)

Download: …”

SDL2 is simple DirectMedia layer – a code library framework that handles graphics, audio, and user input. You can install SDL2 from the website as a macOS framework in /Library/Frameworks, but Basilisk II has a copy of the framework built into it.

Basilisk II has been ported to run on macOS and older versions of Windows, most X11-based versions of Unix, and some older legacy operating systems.

After downloading Basilisk II, you will first need to do some configuration. Along with Basilisk II you'll also need copies of the original Macintosh ROMs from the classic 512KB or 1MB Mac, Mac II, and the original version of Mac OS you want to run (System 7.1, 7.5.3, Mac OS 8 or 8.1). ).

Also from the forum page:

“The new BasiliskII setup requires the BasiliskIIGUI app and a keycode file.”

The keycode files are only needed if you are not using a US-English keyboard.

To get the original Mac ROM files, you need to have one of the mentioned original Mac computers and save its ROM to a file. For copyright reasons, we won't go into detail on how to do this here.

Apple provides a free online download of MacOS 7.5.3, one of the last commercial versions of System 7.

On the original Macs, most of the OS and APIs were implemented in hardware in ROM on the motherboards . The OS could later be extended by installing software, but all older versions and applications of Mac OS called ROM APIs to standardize many of the software's features.

Before continuing, be sure to read the Basilisk II README file for more information. You will also need to read the Technical Manual, which is linked at the top of the Basilisk II home page.

The Basilisk II GitHub page also has a Mac OS 9 emulator called SheepShaver, which emulates later PowerPC-based Macs. Mac OS 9.0, 9.1 and 9.2.1, running on PowerPC, were the last versions of Apple's classic OS before Apple released Mac OS X in 2000.

Note that when Apple released its revolutionary new Mac computers in 1998 (iMac, PowerMac G3 and the first iBook), it switched to a new ROM format called “NewWorld” ROM. Depending on whether you want to emulate a pre-1998 or post-1998 Mac, you'll need “Old World” or “New World” ROMs.

Mac computers from 1998 and newer also switched to new firmware called Open Firmware. You can boot any classic PowerPC-based Mac from 1998 or later with open firmware by holding down Command-Option-OFon the Mac keyboard after reboot.

The original version of the system is 7.5.

Installing Basilisk II

Basilisk II emulates either a Macintosh Classic, Classic II (the last of the black-and-white “compact Macs”), a Macintosh II running MacOS 7.x, 8.0 or 8.1, or a successor to the Mac II line called Quadra . The Macintosh II was Apple's first color Macintosh and had the form factor of a large, wide desktop computer without a built-in display.

The original Mac II models were, in order:

  1. Mac II
  2. Mac IIcx
  3. Mac IIci
  4. Mac IIvx
  5. Mac IIsi

The original Mac II. Note the two 3.5-inch floppy drives at the top right.

Models IIcx and IIvx did not last long. By far the most popular of the Mac II models was the Mac Iici, which was much smaller and easier to handle than the original Mac II.

Apple later replaced the Mac II line with the new Quadra line, as it was based on the next evolution of the 68000 – 68040. These models included the Quadra 700, which looked like an IIci, and two huge desktop computers. Tower models: 900 and 950.

700 has become one of Apple's most popular models.

The IIsi was a cheaper, more compact version of the Mac IIci with more limited features and only one expansion slot.

Macintosh IIsi – uses a design language that Apple called “Snow White”.

To get instructions for installing Basilisk II, you need to clone macemu GitHub repository on Christian's GitHub page, dive into the /macemu/BasiliskII/folder and read the INSTALL.

If you are running on a UNIX system other than macOS, you will need to compile Basilisk II from source on that platform, as detailed in the INSTALL file.

As stated in the INSTALL file:

“The ROM file must be named “ROM” and located in the same directory as the Basilisk II executable file, but you can specify a different location for the ROM file using the “ROM” option” in the settings file (or using the settings GUI).”

If you try to run Basilisk II without the ROM file, nothing will happen.

For the latest complete setup information, see Important page Set up System 7.5.3 with BasiliskII for OSX/macOS.

According to this page, you need to create a folder in your user's home folder named “BasiliskII” and place the application, any keyboard key code files, ROM file and other related files mentioned.

You will also need the mentioned Basilisk II GUI beta application, which is used to install and configure the emulator.

Please note that the GUI setup app can only be downloaded from another related forum post. The current version at the time of writing is 0.20.

There is also another third-party utility called “Basilisk II Disk Image Chooser” that helps you select and configure disk images.

The Basilisk II GUI has a pop-up menu to configure the Mac model, but currently only two models are available from the pop-up window: Mac Iici (7.x system) and Quadra 900 (for Mac OS 8. x). .

The Basilisk II GUI also provides a Browse button for selecting a ROM file using the standard macOS file open panel, which allows you to select a ROM file located in a different location.

Select your Mac model, ROM file, and processor type, then click Save.

The first time you launch Basilisk II, an invisible preferences file will be created in the root of your user folder called “.basilisk_ii_prefs”. Although this file has no extension, it is a plain text file that you can open in any text editor to change some Basilisk II settings.

Some important values ​​in the settings file:

  1. displaycolorlength
  2. ramsize
  3. fpu (floating point unit)


  4. nosound
  5. rom
  6. disk

The value of “rom” is crucial – it indicates the used Mac ROM file. But we'll come back to this a little later.

You can also install or add classic 1.44 MB floppy drives to a prefs file from the GUI or by adding “floppy” keys with the paths to the floppy images you want to use.

The original Macs used standard 3.5-inch floppy disks developed by Sony, which were housed in a sealed plastic case with a sliding metal door that exposed the disk media when the floppy disk was inserted into the drive. You can make images of these disks and load them into Basilisk II.

They were called “floppy disks” because the disk itself was a thin plastic film with a magnetic recording surface attached to it. If you remove the outer hard plastic shell, the disc will “flip” if you lift it.

A stack of 3.5-inch floppy disks.

You will also need to specify the disk (volume) to boot. This is different from installing a ROM file.

The ROM file contains only the Mac OS ROM code. To boot the emulator, you will still need a boot disk with the actual Mac OS operating system.

If you do not set both parameters, the emulator will not start. Back in the Basilisk II GUI, you can configure disk volumes in the Volumes tab:

Set disks, volumes, and shared folder in the Volumes tab.

If you're not sure what to add here, add DiskTools_MacOS8.image, as indicated on the forum settings page.

It is best to launch a third-party application Basilisk II Disk Image Chooser. This app detects if you don't have a boot disk set in your emulator's configuration, and if you don't have one, you'll be prompted for options to configure it:

Set boot disk in the disk image picker .

You may want to first exit the Basilisk II GUI before running the Basilisk II Disk Image Selector, and then restart it after installing the boot disk.

If you click the Select button in the Basilisk II disk image picker, you can select the disk image to use and the utility will install it for you in the emulator settings file.

As soon as you try to exit the Basilisk II disk image selector, it will ask you if you want to burn a settings file. If you do this, you will be prompted to launch Basilisk II, return to the main menu, or exit.

Select Run Basilisk II to launch the emulator, or Exit to exit the Basilisk II disk image picker and return to the Basilisk II GUI to completion. configuration.

If you open the .basilisk_ii_prefs file again, you will notice that several entries have been added. Specifically, the “rom” and “disk” entries, which point to the ROM file and boot disk that will be used when running the emulator.

For example:

rom /Volumes/Virtualization/BasiliskII/9779D2C4 – MacII (800k v2).ROM

disk /Volumes/Virtualization/BasiliskII/DiskTools_MacOS8.image

Make sure the boot disk image file you select matches the Mac model (ROM) you choose to use. Some older Macs don't support newer versions of Mac OS, and vice versa.

If you open the Basilisk II GUI again, in the Volumes tab you will see the boot disk image installed for you by the Basilisk II disk image picker:

The boot disk is installed.

The boot disk is installed.

Shared Files

As stated in the instructions, UNIX Root under the Volumes tab Basilisk II's GUI can be configured to point to a shared folder on your modern Mac's file system—any files you place in the UNIX root folder will appear on the emulated Mac OS desktop. like a UNIX disk volume.

You can copy files from a modern Mac to the desktop of an emulated Mac by placing them in this folder. Please note that you will need to restart the emulator for any changes to be noticed.

Starting the emulator

Once you are satisfied with all the settings in the Basilisk II GUI, click Save button, then click Start. The emulator will start from the boot disk you installed.

When you are finished using Basilisk II and want to exit the emulator, select the Quit menu item from the Special Finder menu in the old (emulated) Mac OS. where you work.

Unlike modern macOS, the Shut Down menu item is located on the right side of the menu bar in the old Mac OS under the Special menu.

Although Basilisk II is a little confusing to install and configure at first, it is good software. Once you have everything installed, it will be easy to use.

The ability to run both System 7.5.3 and Mac OS 8 on modern Macs opens up your computer to a huge library of legacy software that ran on Macs in decades past.

Leave a Reply

Your email address will not be published. Required fields are marked *