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Tricky68k

Tricky68k is a Motorola 68000 simulator for macOS, based on Volker
Barthelmann's VASM assembler, the GNU binutils package, Karl Stenerud's Musashi emulator, and the Fragaria editor.

Tricky68k was tested on OS X Yosemite and later, up to macOS Catalina.

About the Teletype

The simulator implements a single I/O device (the teletype), mapped from 0xFFE000 to 0xFFFFFF inclusive.

  • You write a (16 bit) word to that range to output a character to the teletype
  • You read from the same range to fetch character from the keyboard FIFO. If the keyboard FIFO is empty, -1 will be read. No interrupts are fired when the FIFO gets data, so you need a loop which waits until a character is read:
fetchChar:
  move.w $FFE000,d0
  bmi fetchChar         ;Loop while reads a < 0 value
  ;Read something > 0 => got a character