The Evaluation Of The Microprocessor. Essay, Research Paper
The Evaluation of the Microprocessor.
The microprocessor has changed a lot over the years, says (Michael W.
Davidson,http://micro.magnet.fsu.edu/chipshot.html) Microprocessor technology
is progressing so rapidly that even experts in the field are having trouble
keeping up with current advances. As more competition develops in this $150
billion a year business, power and speed of the microprocessor is expanding at
an almost explosive rate. The changes have been most evident over the last
decade. The microprocessor has changed the way computers work by making them
faster. The microprocessor is often called the brain of the C.P.U.(or the
central processing unit)and without the microprocessor the computer is more or
less useless. Motorola and Intel have invented most of the microprocessors over
the last decade. Over the years their has been a constant battle over cutting
edge technology. In the 80’s Motorola won the battle, but now in the 90’s it
looks as Intel has won the war.
The microprocessor 68000 is the original microprocessor(Encarta 95). It was
invented by Motorola in the early 80’s. The 68000 also had two very distinct
qualities like 24-bit physical addressing and a 16-bit data bus. The original
Apple Macintosh ,released in 1984, had the 8-MHz found at the core of it. It
was also found in the Macintosh Plus, the original Macintosh SE, the Apple
Laser-Writer IISC, and the Hewlett-Packard’s LaserJet printer family. The
68000 was very efficient for its time for example it could address 16 megabytes
of memory, that is 16 more times the memory than the Intel 8088 which was found
in the IBM PC. Also the 68000 has a linear addressing architecture which was
better than the 8088’s segmented memory architecture because it made making
large applications more straightforward.
The 68020 was invented by Motorola in the mid-80’s(Encarta 95). The 68020 is
about two times as powerful as the 68000. The 68020 has 32-bit addressing and a
32-bit data bus and is available in various speeds like 16MHz, 20MHz, 25MHz, and
33MHz. The microprocessor 68020 is found in the original Macintosh II and in the
LaserWriter IINT both of which are from Apple.
The 68030 microprocessor was invented by Motorola about a year after the 68020
was released(Encarta 95). The 68030 has 32-bit addressing and a 32-bit data bus
just like it’s previous model, but it has paged memory management built into it,
delaying the need for additional chips to provide that function. A 16-MHz
version was used in the Macintosh IIx, IIcx, and SE/30. A 25-MHz model was used
in the Mac IIci and the NeXT computer. The 68030 is produced in various
versions like the 20-MHz, 33MHz, 40-MHz, and 50MHz.
The microprocessor 68040 was invented by Motorola(Encarta 95). The 68040 has a
32-bit addressing and a 32-bit data bus just like the previous two
microprocessors. But unlike the two previous microprocessors this one runs at
25MHz and includes a built-in floating point unit and memory management units
which includes 4-KB instruction and data coaches. Which just happens to
eliminate the need additional chips to provide these functions. Also the 68040
is capable of parallel instruction execution by means of multiple independent
instruction pipelines, multiple internal buses, and separate caches for both
data and instructions.
The microprocessor 68881 was invented by Motorola for the use with both
microprocessor 68000 and the 68020(Encarta 95). Math coprocessors, if supported
by the application software, would speed up any function that is math-based.
The microprocessor 68881 does this by additional set of instructions for high-
proformance floating point arithmetic, a set of floating-point data registers,
and 22 built-inconstants including p and powers of 10. The microprocessor 68881
conforms to the ANSI/IEEE 754-1985 standard for binary floating-point
arithmetic. When making the Macintosh II, Apple noticed that when they added a
68881, the improvement in performance of the interface, and thus the apparent
performance was changed dramatically. Apple then decided to add it as standard
equipment.
The microprocessor 80286, also called the 286was invented by Motorola in
1982(Encarta 95). The 286 was included in the IBM PC/AT and compatible
computers in 1984. The 286 has a 16-bit resister, transfers information over
the data bus 16 bits at a time, and use 24 bits to address memory location. The
286 was able to operate in two modes real (which is compatible with MS-DOS and
limits the 8086 and 8088 chips) and protected ( which increases the
microprocessor’s functionality). Real mode limits the amount of memory the
microprocessor can address to one megabyte; in protected mode, however the
addressing access is increased and is capable of accessing up to 16 megabytes of
memory directly. Also, an 286 microprocessor in protected mode protects the
operating system from mis-behaved applications that could normally halt (or
“crash”) a system with a non-protected microprocessor such as the 80286 in real
mode or just the plain old 8088.
The microprocessor 80386dx also called the 386 or the 386dx was invented in
1985(Encarta 95). The 386 was used in IBM and compatible microcomputers such as
the PS/2 Model 80. The 386 is a full 32-bit microprocessor, meaning that it has
a 32-bit resister, it can easily transfer information over its data bus 32 bits
at a time, and it can use 32 bits in addressing memory. Like the earlier 80286,
the 386 operates in two modes, again real (which is compatible with MS-DOS and
limits the 8086 and 8088 chips) and protected ( which increases the
microprocessor’s functionality and protects the operating system from halting
because of an inadvertent application error.) Real mode limits the amount of
memory the microprocessor can address to one megabyte; in protected mode,
however the total amount of memory that the 386 can address directly is 4
gigabytes, that is roughly 4 billion bytes. The 80386dx also has a virtual mode,
which allows the operating systems to effectively divide the 80386dx into
several 8086 microprocessors each having its own 1-megabyte space, allowing each
“8086″ to run its own program.
The microprocessor 80386sx also called the 386sx was invented by Intel in 1988
as a low-cost alternative to the 80386DX(Encarta 95). The 80386SX is in essence
an 80386DX processor limited by a 16-bit data bus. The 16-bit design allows
80386SX systems to be configured from less expensive AT-class parts, ensuring a
much lower complete system price. The 80386SX offers enhanced performance over
the 80286 and access to software designed for the 80386DX. The 80386SX also
offers 80386DX comforts such as multitasking and virtual 8086 mode.
The microprocessor 80387SX also called the 387SX was invented by Intel(Encarta
95). A math, or floating-point, coprocessor from Intel for use with the 80386SX
family of microprocessors. The 387sx is available in a 16-MHz version only, the
80387SX, if supported by the application software, can dramatically improve
system performance by offering arithmetic, trigonometric, exponential, and
logarithmic instructions for the application to use-instructions not offered in
the 80386SX instruction set. The 80387SX also offers perfect operations for sine,
cosine, tangent, arctangent, and logarithm calculations. If used, these
additional instructions are carried out by the 80387SX, freeing the 80386SX to
perform other tasks. The 80387SX is capable of working with 32- and 64-bit
integers, 32-, 64-, and 80-bit floating-point numbers, and 18-digit BCD (binary
coded decimal) operands; it coincides to the ANSI/IEEE 754-1985 standard for
binary floating-point arithmetic. The 80387SX operates individually on the
80386SX’s mode, and it performs as expected regardless of whether the 80386SX is
running in real, protected, or virtual 8086 mode.
The microprocessor mi486 also called the 80486 or the 486 was invented in 1989
by Intel(Encarta 95). Like its 80386 predecessor, the 486 is a full-bit
processor with 32-bit registers, 32-bit data bus, and 32-bit addressing. It
includes several enhancements, however, including a built-in cache controller,
the built-in equivalent of an 80387 floating-point coprocessor, and provisions
for multiprocessing. In addition, the 486 uses a “pipeline” execution scheme
that breaks instructions into multiple stages, resulting in much higher
performance for many common data and integer math operations.
In conclusion it is evident by the following that microprocessors are developing
at leaps and bounds and it is not surprising that if by the time it hits the
teacher’s desk or by the time you read this the next superchip will be
developed(Encarta 95).
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