Motorola 68010

The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982 as the successor to the Motorola 68000. It fixes several small flaws in the 68000, and adds a few features.
The 68010 is pin-compatible with the 68000, but is not 100% software compatible. Some of the differences were:
Additionally, the 68010 has a "loop mode" which accelerates loops consisting of only two instructions, such as a MOVE and a DBRA. The two-instruction mini-loop opcodes are prefetched and held in the 6-Byte instruction cache while subsequent memory read/write cycles are only needed for the data operands for the duration of the loop. It provided for performance improvements averaging 50%, as a result of the elimination of instruction opcodes fetching during the loop.
In practice, the overall speed gain over a 68000 at the same frequency is less than 10%.
The 68010 could be used with the 68451 MMU. However, aspects of its design, such as its 1 clock memory access penalty, made this configuration unpopular. Some vendors used their own MMU designs, such as Sun Microsystems in their Sun-2 workstation and AT&T UNIX PC/3B1.
The 68010 was never as popular as the 68000. However, due to the 68010's small speed boost over the 68000 and its support for virtual memory, it can be found in a number of smaller Unix systems, both with the 68451 MMU (for example in the Torch Triple X), and with a custom MMU (such as the Sun-2 Workstation, AT&T UNIX PC/3B1, Convergent Technologies MiniFrame, the NCR Tower XP and early HP 9000s like the Model 300 and 310) and various research machines. Most other vendors stayed with the 68000 until the 68020 was introduced. Some owners of Amiga and Atari ST computers and Sega Genesis game consoles replaced their system's 68000 CPU with a 68010 to gain a small speed boost.