🚀 go-pugleaf

In article <63320008@hpl-opus.HP.COM> knotts@hpl-opus.HP.COM (Tom Knotts) writes:
>
>>with 486's just coming out, they are becoming the "premium" computer
>>and the 386's have little hope but to drop in price.  the 286 is going
>>to have to become _real_ cheap for people to keep buying them over
>>386sx's.
>
>I hate to admit to being uninformed, but I've been wondering what is the
>difference between the 386 and 486. Can one eventually upgrade a 386 machine
>to a 486?
>
>tom

Don't worry, most of us are also, but don't admit it. The 486 runs the same programs
as the 386 and has added 6 instructions, these are:

	Byte swap (BSWAP)	will move the bytes in the operand around from 
				little indian to big indian and vice versa
	Exchange-and-Add (XADD) good for multiprocessing operation
	Compare-and-Exchange(CMPXCHG) dittio
	Invalidate Data Cache (INVD)	self evident
	Write-back and Invalidate Data Cache (WBINVD)
	Invalidate TLB Entry (INVLPG)

these instructions add some needed functionality to the 486 for system level 
operations.

The 486 has on-chip a 487 processor and 8k of cache memory. RISC type of
technology has been used to reduce the number of cycles needed to executed
one instruction, thus allowing it to have a higher MIPS rating than the
386.

A 486 25Mhz PC, as far as I see in the rates is 10-15 MIPS.

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