Differences between current version and predecessor to the previous major change of 680x0.
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| Newer page: | version 11 | Last edited on Thursday, July 7, 2005 9:54:26 am | by AristotlePagaltzis | |
| Older page: | version 6 | Last edited on Saturday, March 19, 2005 11:40:35 am | by AristotlePagaltzis | Revert |
@@ -1,5 +1,23 @@
-A series
of [CPU]s made by [Motorola].
+A family
of [CPU]s made by [Motorola], sometimes also referred to as "68k"
.
-Introduced by Motorola in September 1979, this is the first in the [680x0] series. It
has 16 32-bit registers, split into 8 data and 8 address. Addressing was done in 32-bits, though the address bus was only 24-bits (later models expanded it to the full 32-bits). Instructions
are multiples of 16-
bits and all addresses
have to be 16-bit aligned (except for addressing single bytes
, of course)
.
+The design
has 16 32-bit registers, split into 8 data and 8 address registers
. The instruction set is quite orthogonal and instructions
are always
multiples of 16 bits in length. Accesses to anything larger than a byte
have to be 16-bit aligned. Overall
, the architecture has a strong [RISC] feel to it, though it is not. It has always been fully 32-bit, as opposed to the [x86] design, which started out as a 16-bit design that was painfully evolved to 32-bit
.
-The [68000|
68000] was used in the
AppleLisa and AppleMacintosh as well as
the AtariST,
Sega ~MegaDrive and some
SunMicrosystems workstations. The 68000 was succeeded
by the 68010
in 1982 which allowed
the use
of virtual memory and fixed
a bug where
the address
of where
a memory exception occured was incorrect
. The 68k was used up until recently in PalmPilot
[PDA
]s
.
+The 68000, the first in the series, was introduced in September 1979, and only had a 24-bit address bus. The 68010, introduced in 1982, allowed the use of VirtualMemory, but most customers decided the [MMU
] alone offered insufficient advantage to justify the expense over its predecessor, so they waited for the 68020 instead. The 68020, which debuted in 1984,
was fully 32-bit, and software could immediately take advantage of this because the architecture had always been designed for the fact. The 68k family enjoyed wide deployment, and is nowadays still
used in embedded devices. Some architectures built around this [CPU] family include:
+
+* The
AppleLisa and the AppleMacintosh.
+* The Commodore [Amiga].
+* The [Atari] ST.
+* The
Sega Genesis and
~MegaDrive.
+* The [HP] 9000/300 series.
+* The Q40
and Q60 (Sinclair QL successors).
+* The [NeXT] workstation.
+* The original
SunMicrosystems [UNIX] machines.
+* The Apollo/Domain
workstations.
+* VMEbus single-board computers from BVM, Motorola and Tadpole.
+* Until recently, the PalmPilot [PDA]s.
+* In any number of lasers printers, such as [HP], Printronix, [Adobe], [IBM], Lexmark and others more.
+* In countless architectures, as peripheral controllers and signal processors.
+
+
The original
68000 design
was in production
by Motorola up until 2000, and is still
in production under license by others, along with its successors and many licensed derivatives of all
the designs
of the family. Innumerable devices employ these [CPU]s even today.
+
+You can run [Linux] on
a range of [680x0]-based systems thanks to
the effort
of the [Linux/m68k project | http://www.linux-m68k.org/]. Ports exist to
a variety of systems; f
.ex., on later AppleMacintosh~es that use the 68030 and upwards (such as the SE30), its
[Linux/mac68k subproject | http://www.mac.linux-m68k.org/
] allows running [Debian]. See the [Linux/m68k project | http://www.linux-m68k.org/] for more architectures
.
