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Although it is frequently characterized as a “16/32‑bit” processor, its design exhibits a unique hybrid architecture: the programming model is 32‑bit (with 32‑bit registers and a 32‑bit instruction set), yet its data arithmetic is carried out by a 16‑bit arithmetic logic unit (ALU) and it utilizes a 16‑bit external data bus. Its 24‑bit address bus enables direct access to 16 megabytes of memory, a very large space for the era. This innovative compromise helped lower chip pin count and cost while delivering performance that spurred a generation of computing systems.
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= Architecture =
This comprehensive and flexible instruction set was one of the reasons the 68000 became popular in systems that required multitasking and graphical interfaces, such as early Macintosh and Amiga computers.
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= Historical Context and Development =
The success of the 68000 spurred a family of processors (68010, 68020, 68030, 68040, 68060) that gradually incorporated full 32‑bit ALUs, on‑chip caches, and integrated MMUs. Despite these advances, the original 68000 remained widely used for many years, with its derivatives still found in embedded systems even after desktop computing shifted toward RISC and x86 architectures.
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= Applications =
* Video Game Consoles: Systems such as the Sega Genesis (Mega Drive) and arcade platforms utilized the 68000 to deliver high performance in graphics and sound processing.
* Embedded Systems: The processor’s cost‑effectiveness and robust design made it popular for industrial controllers, laser printers, and other embedded devices. Even decades later, derivatives of the 68000 architecture (such as ColdFire and DragonBall) continue to be used in specialized applications.
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= Links =
*[[Media:MC68000 User's Manual.pdf|Motorola MC68000 CPU User's Manual]]
*[http://os9projects.com/CD_Archive/TUTORIAL/REF/CARD/68000_Ref_Card.pdf 68000 - Programmer's Instant Reference Card]
*[https://raw.githubusercontent.com/larsbrinkhoff/m68k-microcode/master/doc/Yacht.txt Yet Another Cycle Hunting Table]
*[https://pasti.fxatari.com/68kdocs/68kPrefetch.html Instruction Prefetch documentation]
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[[Category:Non CPC Computers]]
[[Category:Electronic Component]]
