What's the difference between 16 bit and 32 bit memory addressing?

Wintellect

Step 2 of 2:

You forgot to provide an Email Address.

This email address doesn’t appear to be valid.

This email address is already registered. Please login.

You have exceeded the maximum character limit.

Please provide a Corporate E-mail Address.
- I agree to TechTarget’s Terms of Use, Privacy Policy, and the transfer of my information to the United States for processing to provide me with relevant information as described in our Privacy Policy.
Please check the box if you want to proceed.
- I agree to my information being processed by TechTarget and its Partners to contact me via phone, email, or other means regarding information relevant to my professional interests. I may unsubscribe at any time.
Please check the box if you want to proceed.

Could you possibly outline the difference between 16 bit and 32 bit memory addressing and explain how older 16 bit programs work on modern 32bit operating systems?
Whole books can be written on topics like this. Basically, what Windows 2000 does is implement a complete virtual machine (VM) in NTVDM.EXE (NTVDM == NT Virtual DOS Machine). That provides the loader and executer for the 16-bit programs. Unlike cross machine VMs, NTVDM is a little simpler in that it does not have to provide the execution engine because it can just pass the instructions right on to the CPU to execute. From what I gather in talks with people on the Windows team at Microsoft, NTVDM is essentially a complete copy of Windows 3.1.

This was last published in October 2001

Dig Deeper on 64-bit Architecture for Windows

All
News
Get Started
Evaluate
Manage
Problem Solve

Related Q&A from John Robbins

What is a JAD session?

What is a JAD session? This term is referred to often in job postings and seems like some kind of brainstorm you carry out with a client to define IT... Continue Reading

Is there a file file associated with the BackgroundImage property?

How do I convert a VB6 application to VB.NET?

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

Meet all of our Windows Server experts

View all Windows Server questions and answers

SearchServerVirtualization

Hybrid cloud advantages and disadvantages explained

Hybrid cloud is touted as providing the best of both private and public clouds, but this type of infrastructure comes with its ...

Best practices for sizing a server

Serving sizing requires a number of comparisons, especially between having a few large servers or many popcorn servers. Compare ...

Overcome hybrid cloud deployment challenges

Before adopting a hybrid cloud, think about how it will benefit the business and the ultimate goal. Also, hire IT staff with the ...

SearchCloudComputing

Microsoft takes holistic approach to IoT security concerns

Azure Sphere extends security from the cloud to the device. It's the most holistic approach on the market and provides another ...

Get started with Red Hat OpenShift Container Platform

Despite its benefits, Red Hat OpenShift is just one technology amid a growing list intended to simplify container management and ...

Compare management options for Google Kubernetes Engine

Google supports various management options for its Kubernetes Engine service, and while each has its pros and cons, you should ...

SearchExchange

Cloud-based email security tools barricade entry to Exchange

The pressure is on Exchange administrators to avoid a ransomware outbreak that cripples the on-premises email system. Cloud-based...

Migrating public folders requires extensive planning

Do your homework to find the right option for public folders when making a move to Exchange Online. Here are guidelines to help ...

Using Microsoft Exchange certificates requires planning

Exchange certificates typically require minimal management effort after they have been set up, and they offer a secure means of ...

SearchSQLServer

Why running SQL Server on Docker is no longer frowned upon

Microsoft now lets SQL Server databases run in Docker containers, a capability that depends on using volumes to store data in a ...

What the Microsoft GDPR compliance toolkit offers for SQL Server

The set of GDPR compliance tools that Microsoft offers for SQL Server is designed to make it easier for users of the database ...

How much do you know about the components of SQL Server?

From SQL Server Machine Learning Services to the SQL Server Operating System, there's a lot to know about SQL Server. Test your ...

SearchEnterpriseDesktop

Workflow automation software improves LA court productivity

Court's in session, and the jury is unanimous: Automation software can help IT departments provide simpler workflows for end ...

How to create a custom Windows 10 image for deployment

IT pros can build a Windows 10 image with custom apps, Start menu tools and more that they can easily deliver throughout the ...

Four Windows 10 built-in security features to know

IT needs an effective plan to maximize security for Windows 10 and get the most out of its built-in features.

SearchVirtualDesktop

Understand the benefits of user profile management software

Profile management tools can be valuable assets to address failure recovery, migration support, KPI improvement, as well as ...

Citrix Synergy 2018 conference coverage

Citrix Synergy is May 8-10 in Anaheim, Calif. Stay up to date on all the news and analysis that comes out of the conference.

Ten Citrix Synergy 2018 sessions to attend

Get a jump start on your Citrix Synergy planning with this rundown of 10 interesting sessions that explore Linux-based virtual ...

Related Resources

Dig Deeper on 64-bit Architecture for Windows

Related Q&A from John Robbins

Have a question for an expert?

Start the conversation

0 comments

Register

Login

Forgot your password?

Your password has been sent to:

Please create a username to comment.