PROM Revision

[Patel Maqbool 387-1784]

We just got our SunOS 4.1 release. The release manual says that the prom
revison on the Sun 4/260 and the Sun 4/110 has to be at least 2.x. However
we have rev 1.3 on our Sun 4/260 and 1.8 on our Sun 4/110. Can we still
load 4.1? If not, why?

Related question : 

1) What does the PROM have in it apart from the SUN Logo and boot device
   information?
2) Why does this need to be revised?
3) Since it is EPROM, why hasn't SUN come up with a program which will
   write in to the EPROM and revise it as neccessary? (May be a stupid
   question)

Thanks
Patel Maqbool
patel at cvlsun1.ece.drexel.edu