Atari ST · STE · Mega ST · Mega STE

Jackintosh

Switch on your Atari. A Macintosh Plus comes up.

The genuine Mac Plus ROM runs natively on the Atari's own 68000: the happy Mac, System 6, the Finder and the Mac software of 1986 to 1990, from virtual floppies and hard disks on a microSD card. No TOS, no GEM, no emulator program: the Atari is the Mac from the moment you power it on.

Build your image → Drop in your own Mac Plus ROM and get the image for the SidecarTridge TOS Emulator. It is all done in your browser: your ROM never leaves your computer. How it works → The tricks that make a 1986 Macintosh ROM run on an Atari: memory maps, interrupts, the Mac's missing chips, and a cartridge that serves disks.

Why “Jackintosh”?

In 1985 Jack Tramiel, who had just bought Atari, launched the Atari ST: a 68000, a mouse, a windowed desktop and a sharp monochrome screen, at a fraction of the Macintosh's price. The press called it the “Jackintosh”.

Forty years later the joke comes true: with the right ROM in its sockets, the Atari ST boots as a Macintosh Plus. Jack is watching.

What you get

  • The genuine Mac Plus ROM (v3), patched in place: the Mac's own code, at full Atari speed.
  • 640×400 on a monochrome monitor, or the classic 512×342 window.
  • Up to 4 MB of Mac RAM.
  • Floppies and a hard disk from the Multi-device's microSD card, swapped from a menu at boot.
  • The clock from the network (NTP) and the Mac's PRAM saved on the card.
  • Mac sound on the STE and Mega STE; the Mega STE at 16 MHz with its cache.
  • Your Atari keyboard: US, French, German, Spanish and UK layouts.

What you need

  • An Atari ST, STF, STFM, Mega ST, STE or Mega STE with a monochrome monitor (an SM124, or any mono display).
  • The SidecarTridge TOS Emulator in the TOS ROM sockets: it serves the Jackintosh image as the Atari's ROM.
  • The SidecarTridge Multi-device in the cartridge port, running the md-jackintosh microfirmware: floppies, hard disk, clock and PRAM.
  • Your own Mac Plus ROM (the v3 ROM, 128 KB): Apple's code is never distributed here.