The ROM (Read-Only Memory) on a Quadra 800 acts as its motherboard firmware. It contains the essential startup code, toolbox routines, and hardware drivers necessary for Mac OS to interact with the CPU, RAM, SCSI, and NuBus slots.
// Opcode: JMP 0x40800000 (Absolute Jump to ROM High Mem) // Opcode: NOP uint32_t jmp_opcode = 0x4EF90000; uint32_t jmp_addr = 0x00800100; // Arbitrary location for our code quadra800rom work
One technician, a grizzled ex-Apple engineer named , had a Quadra 800 in his lab that had been running a BBS for three years. On Feb 29, 1996, at 9:14 AM, it died. He reset PRAM. He swapped RAM. He even replaced the RTC battery. Nothing. The ROM (Read-Only Memory) on a Quadra 800