6 Nov
1998
6 Nov
'98
4:04 p.m.
"Zane H. Healy" <healyzh(a)ix.netcom.com> wrote:
As for a Math CoPro for the 486, I'm not sure I
ever saw a 487 chip, but I
always figured that they took the chips that didn't cut it as a normal
processor but had a good Math CoPro, and sold them as 487's.
No. The 487 is a *fully* functional 486DX, and it has to be, because when
you plug it into a 487 socket it disables your 486SX completely and takes
over.
The 487 is NOT a "math coprocessor". It's a "Marketing
Breakthrough" (*),
or so they had hoped.
The made the pinouts of the 486 and 487 slightly different, so that you
couldn't take out your old 486SX and simply install the 487 in its place,
which would leave you with a spare 486SX to give to a friend, i.e., less
sales of new chips for Intel.
Part of the reason it didn't work out in practice is that 486DX chips
were generally available for less money than the expensive retail-box
487.
Cheers,
Eric
(*) If you're not familiar with the concept of a Marketing Breakthrough,
see this advertisement which appeared in newspapers nationally a few
years ago:
http://www.milk.com/wall-o-shame/dish.html
Note that every statement in the advertisement is literally true; they
even utilize italics to emphasize the fact that the product is nothing
special.
I didn't buy their antenna, but I offered to pay them up to $20 for a
large poster of the advertisement. Unfortunately they never replied.