Whats an A-Trap Award and why should I covet it?
The original Macintosh used a Motorola 68000 processor. Each instruction that the processor could execute was assigned a number. Well, for future expansion options, Motorola didn’t assign every single number to an instruction. Specifically, every instruction that began with hexadecimal “A” was unimplemented. If you gave such an instruction to the processor, it wouldn’t know how to execute it, and would throw an exception that the operating system would have to handle. The clever Mac OS programmers used this mechanism as a space-efficient way for applications to “call” into the operating system. The application would load registers and/or build up the stack, and lay the “trap” instruction which would force the operating system to take control. The OS would figure out what’s going on, Do The Right Thing™, and gracefully return control back to the application. After the hack show, the-guys-that-make-the-rules headed over to Duke’s Hardware, a great old-tyme hardware store, to buy cheap (s
