MacOS/System 0.85

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System 0.85
Kernel version 1.0
CPU Architecture 68k
BIOS date
Key and TCB link N/A

System 0.85 is the earliest leaked version of the Macintosh operating system, released on 24th January 1984. This version was the base for the Tour disk that came with the original Macintosh, and a non-tour version exists but boots only on special development hardware.


  • System icons are of a prototype Macintosh with a Twiggy drive.
  • Folder icons are round.
  • The about box scene is much more simpler, done in MacPaint by Susan Kare, and is in the code, NOT a resource.
  • The Alternate disk (Unknown Disk) system is present
  • Grim Reaper icon in resources (unused)


  • Key Caps crashes the machine and sometimes corrupts the display memory.
  • Alternate Disk system, although unusually unscrapped, goes to the RAM. Opening a application destroys this data.
  • Scroll bars do not grey out when there is no scroll space.
  • Doesn't work with many applications.