The microprocessor has never been limited to Intel. Eventhough the Intel processors are well known, Motorola has its own share of the market.
The 8 bit processors
Motorola
released its first chip in 1975, an 8 bit processor, the 6800. It can address
up to 4 KB of memory and favors the usage of general purpose RAM over registers.
Motorola improved the RAM of the 6800 to 128 bytes and released the chip to
the market as 6802.
Further enhancements to the 8 bit chip produced the 6808/6803. The 6803 has 128 bytes of RAM and runs at a faster clock rate than its Intel competitor at 3.58 MHz. It also has the Universal Asynchronous Receiver/Transmitter (UART) for serial communications and a counter/timer. Several years later, they made the 6809, another 8 bit processor with an improved instruction set.
The 16 bit processors
By the end of the 70s, it had become clear that computer companies were going to use the 16 bit architecture for their computers. Motorola developed its own line of 16 bit microprocessors.
The first was the 68000 which was released in 1978. It had 24 address lines, but communicates outside with 16 bit lines. With its wide address bus, it can address up to 16 MB of RAM directly. It also ran at 16 MHz, and used 16 general purpose registers. The linear address space of the chip also made it easy to program. All in all, the 68000 was much superior than its Intel counterpart. Sun 2, Sun 3, the first Macintoshes, and Amiga used the 68000.
The 32 bit processors
The 32 bit processor version of the Motorola is the 68020. It uses 16 general purpose registers and can access 4 GB of RAM.
The second generation 32 bit processor is the 68030. It is faster than its predecessor and has separate cache for data and instructions, each 256 byte in size.
It has 4 KB of cache one each for data and instructions. It is also fully pipelined (6 stages). The processor has a floating point implementation and uses its on-board math coprocessor for faster handling of computations. This is also one of the first processors to implement a memory management unit.
Further enhancement of the 68040 produced the 68060. This one has a superscalar design, and on-board memory and power management.
The PowerPC
After more than a decade of development, the 680x0 architecture simply ran out of steam, so Motorola teamed up with IBM and Aplle to produce a new microprocessor with improved performance. PowerPC, the MPC601, is a 64 bit superscalar CPU that can effectively execute up to three instructions per cycle. It is also the first implementation of reduced instruction set (RISC) for PC. The MPC601 has a 32 bit address bus, 32 KB of cache memory, and internal math coprocessor.
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