Motorola 68010

The Motorola 68010, also referred to as the 68010 or '010, is a 16/32-bit CISC processor that was produced by Motorola's Semiconductor Products Sector as a modestly updated version of the original Motorola 68000. It was succeeded by the Motorola 68020.

Features
The 68010 includes a tiny cache to accelerate small loops of two instructions. A design error from the 68000 was fixed so that an optional Motorola 68451 memory management unit (MMU) could add support for virtual memory. However, the 68010 is not 100% software compatible with the 68000. The changes include:


 * The MOVE from SR instruction is privileged in the 68010 and can only be executed in supervisor mode, meeting . Because the 68000 offers an unprivileged MOVE from SR, it does not meet them.
 * The MOVE from CCR instruction was added to partially compensate for the removal of the user-mode MOVE from SR.
 * It can recover from bus faults, allowing it to implement virtual memory.
 * The exception stack frame is different.
 * It introduced a 22-bit Vector Base Register (VBR), which allowed the vector to be anywhere in up to 4MB addressable RAM. The 68000 vector table was always based at address zero.

History
The 68010 was released in 1982 and is pin-compatible with corresponding packages of the 68000. Despite rumors of a 68010-based "Turbo Mac" in development for 1986, it was not used in any Macintosh model. Enthusiasts who tested it by attaching it to a Dove accelerator board found that a few programs, such as the Calculator desk accessory, would cause a hard crash. This issue also affected the Calculator program of Amiga computers. Aside from compatibility issues, observed speed increases at the same clock speed ranged from 8% to 50%.

A third party peripheral that used the 68010 was Jasmine's Direct Serve AppleShare file server, delivering performance comparable to a 68030-based Macintosh IIcx, but without the need of a dedicated Mac.