Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!bbn!bbn.com!tchu
From: tchu@bbn.com (Tom Chu)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Protected mode
Message-ID: <37113@bbn.COM>
Date: 11 Mar 89 19:10:06 GMT
References: <12155@swan.ulowell.edu>
Sender: news@bbn.COM
Reply-To: tchu@BBN.COM (Tom Chu)
Organization: Bolt Beranek and Newman Inc., Cambridge MA
Lines: 20

In article <12155@swan.ulowell.edu> jperkins@hawk.ulowell.edu (Whatsup?) writes:
>when my AT clone boots up, I see it test memory normally then it tests it in
>protected mode. What is protected mode, and how can I use it.
>
>Thanks in advance
>
>-jperkins@hawk.ulowell.edu


Protected mode in the 80286 mode is a mode of the 80286 that will allow you to
address up to up to 16 Megabytes of physical memory. The memory management
system of the 80286 also comes into play among other things. In the protected
mode a real operating system is needed to take advantage of the 80286 power.
This operating system right now goes under the name of OS/2. If you want all
the details, you can look up the info in the AT reference manual and an 80286
manual to really understand protected mode operation. All PC-ATs basically run
in real mode, and makes a 286 look like an 8086. This was done by IBM so that
the PC-AT would be compatible with its daddy, the original IBM PC.

					T. Chu