3B1 questions

[sbw at naucse.UUCP]

(This is my third attempt at posting this, if you've seen it before,
 my apologies.  It doesn't appear to have made it off or our local
 system before, however.)

In the cc(1) man page that comes with the newest UNIX Sys V release
for the ATT 3B1, there is information on how to have the C compiler
generate code for a 68881 math coprocessor.  Further, the parts 
list that comes with same lists a MC 68881 as a math acceleration
unit.

On calling around (9 calls - National Parts did not have that
part number lists), I've learned the following.  The 68881 upgrade
for the 3B1 is ~$2,500 (parts only).  Although I want faster
floating point, I'm not particularly interested in spending such
a high percentage of my total system cost to obtain it.  I assume
that such a high price means that there is (at least) an entire
board coming with the 68881.

Does anyone know more about this?  Is there a cheaper way to go?
Please mail me replies, I'll post if there is enough interest.

While I'm at it, does anyone know the cost of moving from a 40MB
disk to a 70MB?  (If the price of the 68881 is any indication, I
don't suppose I'm interested in this either, but I might as well
find out...)

Thanks!
Steve Wampler
{ucbvax, et.al.}!arizona!naucse!sbw