From: tad@wrq.com (Tad Marshall)
Newsgroups: comp.os.ms-windows.programmer.win32
Subject: Re: Features of the Windows NT
Summary: What is NT, anyway?
Date: 13 Jan 93 03:40:22 GMT
Article-I.D.: shelley.1j02v6INN2lf
Organization: Walker Richer & Quinn, Inc., Seattle, WA
NNTP-Posting-Host: elmer.wrq.com

In article <1993Jan12.193949.23528@nobeltech.se> dawe@nobeltech.se (Daniel Wengelin) writes:
>
>Hi all you Windows NT experts!
>
>Having browsed through some of the articles in this newsgroup, I
>find it quite difficult to figure out what Windows NT actually is.
>A lot of technical experts are discussing details, but it's hard
>for the beginner to catch up with the essense of NT.
>
>I would want know what the basic features of the Windows NT are!

You best sources of beginner info are NTFAQ.TXT (a Frequently Asked Questions
file) and "Inside Windows NT" by Helen Custer (Microsoft Press).  But some of
these questions are easy ...

>Is NT an operating system? 

Very much so.

>In that case, what's the process model and scheduling like?

NT's kernel/executive provide an unstructured (flat) process scheme.  NT
supports subsystems for 32-bit Windows, Posix and others, where the subsystem
can impose its own heirarchy.

>How does NT relate to the Posix standard of OS interfacing?

NT provides a Posix subsystem which supports Posix.1 (the basic API).

>Does it distinguish between light-weight and heavy-weight processes?

In NT, the term "thread" is basically your light-weight process.  A thread is
the unit of scheduling.  A thread lives in a process.

>What's the priority range?

Much like VMS, 32 priority levels divided into realtime and dynamic ranges.

>Is dynamic priorities supported?

Yes.

>What's the performance of a context switch on any specified hw?

The product is in beta and hasn't been tuned yet ... who knows?

>How's process communication performed?

Many IPC methods, local procedure call, remote procedure call, shared memory,
semaphores ...

>Built in rendezvous mechanisms?

Lots of semaphore support, if that's what you mean.

>Mailboxes?

Something called mailslots, don't know much about them.

>Is NT distributed? (Weird question, but stilistically required...)

Windows NT supports an RPC that is said to be interoperable with DCE RPC.  Out
of the box, it supports file and print sharing.  Probably depends on exactly
what you mean ...

>In that case, how is the sharing of resources over a network 
>supported by NT? How does NT support remote procedure calls? Remote
>rendezvous? Is the problem of hetrogenous enviroments addressed? 
>(Maybe a 'Float' on an Intel is interpreted as a ?? on the Alpha)

NT supports NetBEUI and TCP/IP transports, LAN Manager-style file and printer
sharing, and DCE RPC.  DCE RPC should handle type conversion.

>Is NT a GUI/window manager/MMI-sw specification?

It's a GUI, the look-and-feel are exactly Windows 3.1.

>In that case, how does it relate to other window managers? Could
>X11 be run on top of NT? At what level of abstraction is the interface?

Several vendors are porting X-servers to NT.  But the underlying GUI is still
NT's Windows 3.1 lookalike.

>Is NT now or later? If later, when? And on what hw?

Now if you want to beta test it or write code for it, later if you want a
tuned debugged OS.  Though there have been several earlier "pre-releases",
the first so-called "beta" was released in October '92, the second beta is
currently scheduled for "1st quarter '93", and the final ship date is "2nd
quarter '93".  A lot of people wish they knew tighter dates than these
(including Microsoft!).

The first release will run on Intel x86, MIPS R-4000 and DEC Alpha ...
there is talk of it showing up on HP PA-RISC, nothing definite yet.  It's
designed to be portable, so it could also show up on IBM/Motorola Power-PC
, Sparc and other architectures.

>As you have concluded, I'm into  distributed real-time systems and know
>_nothing_ about Windows NT. If you've noticed that Ada is the language
>of my application, you're Eagle-eyed and right.
>
>Please help! 
>
>                Yours truely
>                               Daniel
Newsgroups: comp.os.ms-windows.programmer.win32