Motorola 68030 wire wrap prototype

Re:Motorola 68030 wire wrap prototype by kjs3 on Tuesday November 29, 2022 @11:14AM (#33789394)

The 68030 was a 68020 leaving out a couple of rarely used instructions (I don't recall what) and adding a sort-of-but-not-exact subset of the 68851 MMU, 256 byte cache and some bus interface improvements (sync access). That and process improvements made it more efficient than the 68020. Motorola also upped the clock speeds on the 68030 (up to 50MHz).

The EC chips, at least at the beginning, had a defective MMU that was disabled and sold cheaper than a 'full' chip. Fine for the Amiga OS, or embedded stuff. I don't know if they ever made them without the MMU at all. The EC nomenclature extended to the 68040 and 68060, where it meant "no MMU or FPU", and added the LC nomenclature which means "MMU, but no FPU".

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Re:Motorola 68030 wire wrap prototype by jecel on Wednesday November 30, 2022 @04:57PM (#33808408)

The software fad of the late 1970s was modular programming as seen in Ada or Modula-2. Intel supported that with its 286 and it was a key feature of the National 32016, so Motorola couldn't be left behind and added support in the 68020.

Except that by the time the 68020 came out Unix and C were king and C's dirty hack solution to modularity (#include .h files) was now considered good enough. Intel and National kept full backwards compatibility (to this day, in the case of Intel) but Motorola quietly dropped the stuff from the 68030.

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