IEEE SA - 1196-1987 - IEEE Standard for a Simple 32-Bit Backplane Bus: NuBus

Description: The standard describes a computer backplane bus optimized for 32-bit transfers, multiprocessor operations, and simplicity. In brief, this is a synchronous (10 MHz). multiplexed, multimaster bus that provides a strictly fair arbitration mechanism. The only bus transfers are read and write (and block transfer versions of each of these) to a single 32-bit address space. Geographic slot addressing and nondaisy-chain arbitration scheme make system configuration simpler by eliminating switches and jumpers. This minimalist approach results in a conceptually straightforward bus with a small pin count (51 active signal lines).