Setting up System 7.5.3 with BasiliskII for OSX/macOS

(Last updated September 25, 2020)

This guide had been neglected for many years. It is now in the process of being updated. In the meantime there will be inconsistencies between text and images.

(You can also set up Basilisk II for Windows.)


Basilisk II emulates up to a 68040 Macintosh, which can run Mac OS 7.x through 8.1.

This manual was revised with the recommended 4 May 2019 and later 64-bit SDL2 builds in mind.
Setup of most older versions and builds, both PPC and Intel, is similar.

Please note:

  • This manual describes setting up BasiliskII with MacOS 7.5.3 (used to be a free download from Apple), inside a folder called BasiliskII in your Home folder.
  • Changed settings in preferences will take effect after BasiliskII has been newly launched (or started from the BasiliskIIGUI). With only a restart in the emulated machine new settings will not be used.
  • Using most compatible ROM files it is also possible to run up to MacOS 8.1 in Basilisk II.
  • Not covered here, but when installing MacOS from a CD, only generic retail Mac OS install CDs can be used. A system install CD that was originally provided with a new Mac will only install on that specific model. Since OSX 10.8 (Mountain Lion) OSX/macOS does not allow physical CDs to be mounted in the emulator.
  • Not covered here, but a disk image of a retail Mac OS install CD can be used instead of the real CD. The disk image must be in a non-compressed format and the image file must be locked in the Finder to convince the installer that it is on the original read-only CD.

Preparing Your BasiliskII Folder

To start, you need to have some files in your BasiliskII folder:

  1. The BasiliskII application, the actual emulator.
  2. The BasiliskIIGUI application, to be used for setting up and configuring BasiliskII.
  3. A floppy disk image to boot the Mac. Download it here. Unzip the file, and lock it after you moved it into the BasiliskII folder: Select “Get Info” and check the “Locked” box. Use only this floppy image during setup. System 7/7.5 floppy images will make you run into problems later during the installation process, because they don't allow the shared folder to appear on the desktop, see below.
  4. A compatible ROM file. Basilisk II will not run without a compatible ROM file. If BasiliskII does not find a compatible ROM file, it will immediately quit on launch. It may be difficult to get ahold of a compatible ROM file as distributing bare ROM files violates Apple license agreements. ROM files from Quadra and Performa machines work best. Google “redundant robot sheepshaver” for downloads.
  5. A keycodes file. The keycodes file is not necessary if you are using an US English QWERTY keyboard layout.

Creating a shared folder

From within BasiliskII you will have access to a folder on the OSX/macOS side. That folder will appear on the BasiliskII desktop as a disk named “Unix”. Files copied or saved in BasiliskII to the “Unix” disk will appear in the shared folder on the Mac OS X side and files placed in the shared folder on the Mac OS X side will appear in the “Unix” disk in BasiliskII. Before you start configuring BasiliskII, create a folder that can serve as shared folder. The folder can be anywhere it is convenient for you and it can have any name you like.
However, this manual assumes that a shared folder called “Shared” is available on your desktop. Prepare for installation of MacOS by creating the Shared folder on your desktop.

Then download the 19 installer parts for System 7.5.3 and place them in the Shared folder.

Take a look at the file names. If the first is named with a ”.smi” extension and the others with a ”.part” extension, you can skip this step of double-clicking all files individually. Double-clicking the files will unpack them, leaving you with the double amount of files in the folder. When finished, remove the files not named with the “.smi” or “.part” extensions.

Running BasiliskIIGUI

There are different GUI applications available. A 32-bit “BasiliskIIGUI” can be used up to macOS 10.14 (Mojave). A newer 64-bit “Basilisk II GUI” (still in beta) can be used in 10.12 (Sierra) and later. The example images here look different as they are from an even older GUI application, but the actual settings are similar in all GUI versions.

When the needed files are in the Basilisk II folder and when you have created a shared folder with the .smi and .part files in it, you can start configuring Basilisk II:

1. Start BasiliskIIGUI

2. Configure preferences in Volumes tab

Volumes list
BasiliskII will always try to start up from the first entry in this list. We will start up from the floppy disk image you downloaded, so you will need to add that floppy disk image as the first disk to the list. (BasiliskII uses floppy or hard disk image as disks).

- Click “Add” and in the Open dialog select and “Open” the floppy disk image in your BasiliskII folder.

The floppy will show up in the volumes list.

Next, we’ll create a file that will be used as your Mac hard disk to install your future Mac OS on.

- Click “Create”
- Navigate to the folder you want to create the file in
- Give the file a name, name it “MacOS753”
- Set the size for the hard disk. I would recommend 500 or 1000 Mb
- Click Save
(This can take some time, be patient.)

When the file is created, the window will close and you’ll see the preferences editor again. Notice that the hard disk is added to the list of volumes.
Note: In the 64-bit beta Basilisk II GUI, the file will be created but not yet added to the volumes list. You will need to additionally use the “Add” button to add the file to the Volumes list.

For the installer parts to be available later on, we need to create yet another hard disk.
- Click again “Create” to make a hard disk with size of 100Mb and name it “InstallerParts”.

You should now see all three disk image files in the Volumes list:

Unix Root
In order to have the shared folder available to exchange files between OSX and Mac OS, we need to set the location of that folder at “Unix Root”.

Depending on the used GUI, you can use the “Browse” button to find and add the Shared folder on your desktop to the field after “Unix Root” or you may need to type the path to the shared folder in that field. The line below shows what to enter when the folder is called Shared and is located on your desktop:

/Users/hsp/Desktop/Shared (replace the username “hsp” with your username!)

Now click the tab Graphics/Sound on the Preferences editor

3. Configure preferences in Graphics/Sound tab

Video Type
For now, leave the Video Type selection at “Window”.
(After installation you can select “Full Screen” if you want BasiliskII to start up in full-screen mode.)

Window Refresh Rate
Select “Dynamic” for the Window Refresh Rate.
(Only on older PowerPC machines, select a lower refresh rate, e.g. 30Hz. On such machines, 30Hz may improve performance and will lower the extreme CPU hunger of BasiliskII on PowerPC machines.)

Width and Height
Select the desired width and height of the emulator window.
Set lower values than the resolution of your actual screen. If you have a large screen, you can manually enter higher values than those in the menus, for instance 1280 x 800.

The Audio Settings can be ignored.

Move to the keyboard/Mouse tab

4. Configure preferences in Keyboard/Mouse tab

Raw Keycodes
If you keyboard layout is not US English QWERTY:
Check “Use Raw Keycodes” and browse for the BasiliskII_keycodes file in the BasiliskII folder.

Mouse Wheel Function and Lines to Scroll are a matter of taste. The image shows the standard settings.

Move to the Serial/Network tab (in the 64-bit beta Basilisk II GUI: Ports tab)

5. Configure preferences in Serial/Network (or Ports) tab

Ethernet Interface
In order to be able to use the internet in BasiliskII, you need to set the Ethernet Interface (or Ethernet Port) to “slirp“:
Select “slirp” from the menu in the box.

Other settings in this tab can be ignored.

Now move to the Memory/Misc tab (in the 64-bit beta Basilisk II GUI: System tab)

6. Configure preferences in Memory/Misc (or System) tab

Correct settings here are important. If configured incorrectly, setup may fail or BasiliskII may crash.

MaOS RAM Size (MB)
The amount of memory available to Mac OS in Basilisk. Set it to 128 or 256.

Mac Model ID
Set the Model ID to “Quadra 900”.

CPU Type
Set CPU type to “68040”

ROM File
Select the rom file to be used. Click “Browse” and in the Open dialog navigate to the rom file you placed in the BasiliskII folder and Open it.
The path to the rom file should now appear in the text field.

Don't use CPU when idle and Ignore Illegal Memory Accesses
Make sure both options are checked.

Next, click the JIT Compiler tab (in the 64-bit beta Basilisk II GUI: JIT tab)

7. Configure preferences in JIT Compiler (or JIT) tab

Do not enable JIT compiler now!
The other JIT preferences can be set as shown in the image above. You will then only need to check the “Enable JIT compiler” box when you want or need to enable JIT later.

8. Click start!

Click “Start” to save the settings and to start BasiliskII.

If BasiliskII does not start and/or the GUI does not quit, click Start or Save in the GUI to save the settings, quit the GUI application, and launch BasiliskII directly.

In Mac OS

During startup, the system will encounter the floppy and give a warning about running of a floppy disk.

- Click “OK” to proceed.

The system will then find the disks we created earlier, finds them unreadable and will offer to initialize them.

- Give the first disk an appropriate name (we use here “MacOS753”) and click “Initialize”:

- Click “Continue” to proceed with initializing the disk:

- Name the second hard disk “Installer Parts”. Click again “Initialize” and proceed with initializing the hard disk:

Finally, you will see the desktop with icons for the mounted volumes (disks):

  • The startup volume “Disk Tools 1” (the DiskTools_MacOS8 floppy disk image you downloaded)
  • The newly created disk “MacOS753” that you will install the system onto
  • The newly created disk “Installer Parts”
  • The “Unix” volume that gives access to the shared folder on the OSX/macOS side.

- Open the “Unix” disk and copy all 19 files from the “Unix” disk to the “Installer Parts” disk:

- The 19 files are now on the “Installer Parts” disk:

- On the “Installer Parts” disk, double-click the first part called “System 7.5.3 01of19.smi”. A floppy icon will appear on your desktop:

- Double-click that icon to open the floppy image and start the installer contained in the window that opens.

- Choose “MacOS753” to install the system onto and proceed with the system installation.

- When the installation has completed, you can quit the installer.

- Shut Down Mac OS from the Finder Special menu, or quit BasiliskII and choose Shut Down from the dialog.

(If somehow the GUI application is still running, make sure to quit it now.)


- Start BasiliskIIGUI again.

- From the volumes list, remove the “DiskTools_MacOS80.image” and “InstallerParts” disks.

- Click “Start” to save the changed settings and to start BasiliskII.
(Again, if BasiliskII does not start and/or the GUI does not quit, click Start or Save in the GUI to save the settings, quit the GUI application, and launch BasiliskII directly.)

Et voila!

Good to know

The Startup Disk control panel is not functional in BasiliskII
BasiliskII will startup from the first bootable volume in the Volumes list. Trying to use the Startup Disk control panel may cause BasiliskII to crash.

How to enable sound in BasiliskII
In “Sound” control panel, select “built-in” for the output device. In 8.1, the Sound control panel is sometimes installed in the “Apple Extras” folder. You can use it there to select the built-in output device.

How to enable network access
Set the TCP/IP control panel to Ethernet and DHCP. As soon as you start using IP network access, for instance with a web-browser, the IP addresses will become visible in the control panel.

Control-return window/fullscreen toggle
BasiliskII will launch in either window mode or full-screen mode according to the settings in the GUI application. Regardless, you can toggle between window mode and full-screen mode using Control-return.

Control-F5 grabbing mouse cursor toggle
Control-F5 will contain the mouse cursor within the BasiliskII window. This may be useful with some games.

See this guide: Printing from SheepShaver and BasiliskII

See this guide: Appletalk for SheepShaver/Basilisk in Leopard, Snow Leopard or Lion (32 and 64 bit)

The shared folder / "Unix" disk

Transferring files
As explained above, the shared folder that you created in OSX/macOS will appear on the BasiliskII desktop as a disk (a volume) named “Unix”. Files copied or saved in BasiliskII to the “Unix” disk, will appear in the shared folder on the OSX/macOS side and files placed in the shared folder on the OSX/macOS side will appear in the “Unix” disk in BasiliskII. That way you can use the shared folder and the “Unix” disk to transfer or exchange files in both directions.

Applications cannot run properly from the “Unix” disk
If you use the shared folder and “Unix” disk to transfer applications for use in BasiliskII, always copy the applications and related files within BasiliskII from the “Unix” disk to the startup system volume (or to another mounted disk image volume) before actually using them.

Note that moving files directly from the “Unix” disk onto the BasiliskII desktop, does not copy them to the startup system volume. Those files will still be on the “Unix” disk, in fact inside the folder “Desktop Folder” in the shared folder.

Trashing files
Trashing files from the shared folder should be done at the OSX/macOS side. On the Mac OS side, the trash cannot be emptied when it contains files from the “Unix” disk.

Advanced features (SDL2 port builds only)

These features can be activated by manually editing the preferences file (the hidden ~/.basilisk_ii_prefs file).
Note: Saving settings in the GUI application will delete the manually edited entries.

Changing the hotkey
By default, the hotkey used with window/full-screen toggle and mouse grabbing toggle is the Control key (Control-Return and Control-F5). You can change the hotkey by adding a “hotkey” item to the preferences file:

1: control(default)
2: option
3: control+option
4: command
5: control+command
6: option+command
7: control+option+command

For instance, you can set the hotkey to Control-Command by adding this line to the preferences file:

hotkey 5

Offset date in years and/or days (20 February 2019 and later builds)
The date inside BasiliskII can be set in the past or in the future, in years and/or days. This may be needed for using some specific software. Adding these lines to the preferences file will set the date to 25 February 1989 when the actual date on the host is 20 February 2019:

yearofs -30
dayofs +5

Note: This feature can mix up relations between older files and newer files and between files' creation dates and modification dates. It should only be used by experienced users who know what they are doing.

Changing scaling algorithm (Works as intended in 24 February 2019 and later builds)
Using nearest-neighbour or integer scaling will improve display quality when a low resolution emulator screen is displayed on a high resolution monitor (Retina screen). Nearest-neighbour or integer scaling can be applied by adding one or both of these lines to the preferences file:

scale_integer true
scale_nearest true

Enlarging window size (22 September 2020 and later builds)
Enlarge BasiliskII window while preserving guest screen resolution. At next launch, the window will appear twice the set resolution when this line is added to the preferences file:

mag_rate 2

Guest gamma ramp pass on to the host (22 September 2020 and later builds)
With this feature enabled, the guest gamma settings will be passed on to the host. This could improve color and brightness accuracy when guest gamma settings and host screen properties match. There are three possible settings:

gammaramp off
gammaramp on
gammaramp fullscreen

The default is “off”. When set to “fullscreen”, the feature works only in full-screen mode.


Direct questions to our support forum. Note that this guide is partially derived from our SheepShaver for OS X setup guide.

basiliskii_osx_setup.txt · Last modified: 2020/09/25 08:47 by ronald_p._regensburg
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