Help building the largest human-edited directory of the web Suggest URL - Open Directory Project - Become an editor

directopedia.org uses links and structure from dmoz Open Directory Project.
The contents has been generating using technology developed by scientec.

The Motorola 680x0/0x0/m68k/68k/68K family of CISC microprocessor CPU chips were 32-bit from the start, and were the primary competition for the Intel x86 family of chips.

Contents 1 The 68k family members 2 Main uses 3 Architectural heritage 4 Where did the 68050 go? Was there no -070? 5 The next 68k generation 6 Other variants 7 Competitors to the mainstream 68ks

The 68k family members

• Generation one
  • Motorola 68000 a hybrid 16/32 bit chip (16-bit bus)
  • Motorola 68EC000
  • Motorola 68HC000
  • Motorola 68008 a hybrid 8/16/32 bit chip (8-bit bus)
  • Motorola 68010
  • Motorola 68012
• Generation two (fully 32-bit)
  • Motorola 68020
  • Motorola 68EC020
  • Motorola 68030
  • Motorola 68EC030
• Generation three (fully 32-bit)
  • Motorola 68040
  • Motorola 68EC040
  • Motorola 68LC040
• Generation four (fully 32-bit)
  • Motorola 68060
• Others
  • Motorola CPU32 (aka Motorola 68330)
  • Motorola ColdFire
  • Motorola DragonBall

Main uses

The 68k line of processors have been used in a variety of systems, from Texas Instruments calculators up to critical control systems of the Space Shuttle. However, they have become most well-known as processors powering desktop computers such as the Macintosh, the Amiga, the Atari, and others.

Today, these desktop systems are either end-of-line (in case of the Amiga and the Atari), or are using different processors (such as is the case for the Macintosh). Since these desktops are now more than a decade old, the original manufacturers either are out of business, or no longer provide an operating system for the hardware; however, the Debian, NetBSD and OpenBSD operating systems are still supported for m68k processors.

Architectural heritage

People who are familiar with the PDP-11 or VAX usually feel comfortable with the 68000. With the exception of the split of general purpose registers into specialized data and address registers, the 68000 architecture is in many ways a 32-bit PDP-11.

Where did the 68050 go? Was there no -070?

Note that there is no 68050, this is because the design that was destined to be the 68050 was eventually released as a version of the 68040. There is also no revision of the 68060, as Motorola was in the process of shifting away from the 68k and 88k processor lines into its new PowerPC business, so the 68070 was never developed. Had it been, it would have been a revised 68060.

The next 68k generation

The 4th generation 68060 shared most of the features of the Intel P5 architecture of x86. Had Motorola decided to stick with the 680x0 series, it is very likely that the next processor (68080) would have resembled Intel's P6 architecture.

Other variants

After the mainline 68k processors' demise, the 68k family has been used to some extent in microcontroller/embedded microprocessor versions. These chips include the ones listed under "other" above, i.e. the CPU32 (aka 68330), the ColdFire, and the DragonBall.

Competitors to the mainstream 68ks

The principal competitors in the microcomputer market for generation one were the x86 architecture P1 and P2 IA-16 chips (8088, 80286). For generation two, it was the P3 IA-32 chips (80386), and for generation three it was the P4 IA-32 chips (80486). Generation four did compete against the P5 IA-32 chips (Pentiums), but to a lesser extent, as much of the hitherto 68k marketplace was shifting over to the PowerPC, sounding the death knell for the 680x0 on the desktop.

This article is based on the article "68k" from Wikipedia - the free encyclopedia created and edited by online user community. This article is distributed under the terms of GNU Free Documentation License. Here you find the list of authors of this article. The article can only edited within Wikipedia. Edit this article in Wikipedia.