Building BasiliskII for iOS

I’ve had numerous requests for a guide to building BasiliskII on iOS. Let me know of anything is unclear or would benefit from more details!

Note: I’m building with Xcode 11.3.1 on macOS 10.14.6 Mojave, so your experience may be different.


  1. Install Xcode from Mac App Store
  2. Clone project source from GitHub
  3. Switch to the ios branch.
  4. Open .xcodeproj file
  5. Optional: change iOS deployment target (defaults to iOS 8.0)
  6. Set Product > Destination to point to your device
  7. Run

Optional Changes

I plan to add these changes into my own fork of the code. Soon, I promise!

Possible build errors

Error mentioning pointerInteraction This is because of a missing #ifdef, so add one around the if statement at line 82 in

#ifdef __IPHONE_13_4
    if (@available(iOS 13.4, *)) {
        pointerInteraction = [[UIPointerInteraction alloc] initWithDelegate:self];
        [pointingDeviceView addInteraction:pointerInteraction];

Error mentioning qemu I’ve seen this error on macOS 11 Big Sur with Xcode 12. The crux is that the code as it stands will only build with Xcode 11 (the last version was 11.7) so be sure to use that.

Adding chunky screen resolutions

I added chunky “half resolution” screen modes to increase the size of user interface elements so that buttons, menu items and so on are all around the 44pt recommended in the Apple iOS HIG.

For iPad Pro 12.9” these changes were:

[videoModes addObject:[NSValue valueWithCGSize:CGSizeMake(512, 496)]]; // portrait minus keyboard
[videoModes addObject:[NSValue valueWithCGSize:CGSizeMake(512, 672)]]; // portrait "full" scren
[videoModes addObject:[NSValue valueWithCGSize:CGSizeMake(683, 502)]]; // landscape "full" screen

Enter those after line 53 in file

Disabling graphics smoothing

My personal preference is to disable filtering/smoothing on all graphics scaling:

NSString *filter = kCAFilterNearest;
videoLayer.magnificationFilter = filter;
videoLayer.minificationFilter = filter;

Make this change around line 80 in file

Custom Keyboard Layouts

These are defined in JSON and compiled to a custom format:

Here’s one that I made, based on the British layout, for use with Deneba artWORKS/UltraPaint.

Enable Split View Support

This be enabled by changing BasiliskII-Info.plist: UIRequiresFullScreen should be false in BasiliskII-Info.plist but be wary of the following problem:

  • the very top of the screen (where you’d expect the iOS status bar to be, and where part of the System 7 menu bar is) will become unresponsive to touch due to the Slide Over indicator

This would need to be managed/avoided by the screen layout of BasiliskII, but when I attempted this it raised more issues.

However, you can still use Slide Over to position Safari, Files, etc. along the edge of your screen.


There are about capabilities of the emulator integration. I’ll go further into these, and more besides, in a future post.

File Sharing

A drive appears on the desktop that is mapped to the iOS file sharing folder of the app.

  • You can use Files to transfer files into or out of the emulated machine
  • Share Sheet also works for getting files into the emulated machine

Apple Pencil

This is supported the same way as regular touch so it acts as a mouse. Drawing works well and is very responsive, even at lower Hz.

  • Palm rejection is missing
  • Pressure sensitivity is missing
  • Multi touch seems to be missing
Comments: @gingerbeardman