Hi,
The 286, 386, 486 (and even the Pentium 586), were part of the family
of Intel processors based on the 8086 microprocessor. In fact, the
full names are 80286, 80386 and 80486. This is generally known as the
x86 architecture. So the 286 was a continuation of the 186 etc.
The 286 was introduced in 1982 and ran at either 6 or 8Mhz.
The 386 was introduced in 1986 and ran at 25MHz initially, but of
equal importance was the fact that it was now a 32-bit processor.
There were 3 main varieties of the 80386 - the DX, SX (16bit bus) and
the SL (mobile edition).
Then in 1989, came the 486 (i486), again came in DX, SX and SL, but
this time the DX had a floating point processor. This started at 25MHz
for the SX and 33MHz for the DX, but quickly the DX2 and SX2 arrived,
doubling the processor speed. I think there was a DX4 as well, running
at 100Mhz!
So, to answer your question; the 286, 386 and 486 numbers do not
relate to the processor speed (clock speed), rather they are
continuations of a series of processors. There was an 8-bit variant of
the 8086, the 8088 which was continued up to the 80188 and used by
IBM. There were also 8085, 8087, 8008 and 8080. The 8080 paved the
way, and is seen by many as the most important product of the 20th
Century!
The 8, I think refers to the fact that it was an 8-bit chip, as
compared to the 4001, 4002, 4003, 4004 and 4040 which were 4 bit. But
the naming convention seems to have given way to an obvious
continuation, anyway due to problems copyrighting numbers, the 80486
was known as the i486 and the 80586 became the Pentium (64Bit bus).
Hope this answers your question!
Simon |
