# From jfw@jfwhome.funhouse.com Thu Sep 19 05:19:50 1996
#
# Windows NT uses exactly the scheme described.  A DMA driver *always*,
# *unconditionally* allocates a "mapping register" to connect I/O bus DMA
# addresses to memory bus addresses, and *always* deallocates the mapping
# register when DMA is complete.  (Gee, you'd think the NT designers were
# old VAX hacks or something :-).

1.  If you want machine independence, that's certainly one way to do it.

2.  I'm sure you're aware that the project manager for NT was a lead 
programmer for VMS.  It shows that he _still_ doesn't know how to design
an operating system.


# The Hardware Abstraction Layer contains
# *all* of the knowledge about whether a given bus or machine needs registers,
# bounce buffers, or no translation at all.  And while NT's performance may
# suck, this fails to be a source of any perceptable suckage.

Here again, if you want machine independence, that's one way to do it,
and it's probably not all that bad.  In fact, it appeared to me to be
a great principle, but something, somewhere obviously isn't working quite
right because we haven't even seen an alpha release for this kind of
interface.

# 
# You wouldn't want *Windows NT* to be able to claim to be better designed
# and more machine independant than NetBSD, would you?  ;-)

Windows NT will _never_ make either claim.  It runs on a SPIM processor
and an Intel.  Does it actually run on a forward MIPS?

They certainly have made no attempt to port it to the SPARChitecture.

[Thank the High Ones for small favours.]

				--*greywolf;