Eliminating Computer Hardware Conflicts

If you have a problem using Cakewalk, frequently the problem isn't actually with Cakewalk itself. When you get a "General Protection Fault" error message, or when your computer locks up, often this is due to a conflict within your system. Almost everyone who has ever owned a PC has had to deal with these problems and they can be difficult to resolve. But if you want things to work right, you have to bite the bullet and fix them.

The Most Common Type of Conflicts:

There are three very common types of conflicts that can affect Cakewalk.

• IRQ. (Interrupt Request)
• Port Address. (Input/Output or I/O ports)
• DMA. (Direct Memory Access)

You may be asking yourself, "What the heck is an IRQ, Port Address, or DMA?" Good question. Basically, IRQs, Port Addresses, and DMAs are settings for devices connected to your computer. These settings—if correct—enable the devices work with your computer and avoid interfering with each other.

Here's a simple analogy that might help you understand the nature of a conflict. Think of an IRQ as a street address, and think of your computer as the mailman. Then, imagine that both you and your next door neighbor share the same address: 1 Strawberry Lane. What's going to happen when the mailman tries to deliver mail to 1 Strawberry Lane? He's going to see the same address on both mailboxes at which point his brain will start churning and churning so much that he won't know what to do—he'll lock up—he'll freeze—he'll stand there unable to deliver the mail—he'll crash—he'll "General Protection Fault."

This is essentially what can happen when you have two pieces of hardware set to the same IRQ, Port Address, or DMA. So the point is,

No two devices can share the same IRQ, Port Address, or DMA.

Solving Conflicts: The Safe Way

The safe way is the method we recommend, and it requires that you first find out all the IRQ, Port Address, and DMA settings for your hardware. This is a one time procedure that you should probably do anyway to prevent future conflicts. The more devices you have in your computer, the more time consuming it becomes, so you must be prepared sniff around—to be the bloodhound.

Note: There are several utilities that claim to detect conflicts—these are not wholly reliable. Also, just because Windows 95 doesn't report that there is a conflict, doesn't mean there isn't one.

Here are a few places to look that will help you determine your settings:

• In the manual for the device. The manual for the device should give its default settings and will tell you how to adjust the settings.
  
• On the device itself. Many times there are jumpers on the device from which you will be able to determine what it is set to. The jumpers might not be intuitively labeled so please refer to the device's manual to find out what the jumper settings mean.
  
• In the Control Panel. In Windows 95, choose Start | Control Panel | System | Device Manager | Computer | View Resources. This will show the IRQ, Port Address, and DMA setting for many devices.

  Note: Windows is not 100% reliable in detecting conflicts.

• Special software that comes with the device. There are some devices that require special software to manage IRQs and so forth. This might be called "Configuration" software for the device, or "Settings/Setup" software.

Where to change your settings.

There are a few ways to change your settings, but the method is not the same for every device.

• On the device itself. You physically move jumpers/dip switches.
  
• In the Settings for the driver. If you're using multimedia devices in Windows 95, choose Start | Control Panel | Multimedia | Advanced. Once there, you can look in Audio Devices or MIDI Devices and Instruments. To get to the driver's settings, you select the driver, click on Properties, and then choose Settings. In Windows 3.1 or 3.11 you go to Control Panel | Drivers, select the driver, and click on Setup.

  Note: Some devices only require that you change the settings for the driver, while other devices require that you change the settings for the driver and on the device itself.

  Note: Even though your card might be "Plug and Play," there could still be a conflict as "Plug and Play" is not 100% reliable.

• Special software that comes with the device. There are some devices that require special software to manage IRQs and so forth. This might be called "Configuration" software for the device, or "Settings/Setup" software.
  
• Some of the above.
  
• All of the above.

The only way to know for sure how to change the settings is to consult your manual or the device manufacturer.

Getting to the root of the problem.

A good way to find out the source of a conflict is to actually remove devices from the computer. Here's an example:

Pretend the devices in your computer are a MIDI interface and two soundcards: Let's call them the Cool soundcard and the Loser soundcard. Say you suspect the Loser soundcard is the one that is causing the trouble. The best thing to do is to make your system as simple as possible and remove both the Loser soundcard and the MIDI interface.

Note: As well as physically removing the device, you must also remove the device's driver!

The goal here is to see if the Cool soundcard will work by itself. If it does work by itself, then you know that the conflict happens when you introduce the other cards into the system. Next, one at a time, you add back the other cards. Try your system a few different ways:

1. Try the Cool soundcard and the Loser soundcard. Does it work? If so, then you know there is not a conflict between the two of them. If not, then you know they are conflicting and you will have to adjust their settings.
2. Try the Cool soundcard and the MIDI interface. Does it work? If so, then you know there is not a conflict between the two of them. If not, then you know they are conflicting and you will have to adjust their settings.
3. You might even need to try the Loser soundcard and the MIDI interface without the Cool soundcard in your quest to find the conflicting devices.

So, the moral of the story is: Detecting conflicts is best done through a process of elimination. 

The Risky Way—Is There An Easy Way Out?

You now know the safe way. The safe way is the most thorough way to resolve conflicts and to prevent future ones, but if you're the type of person that likes to find an easy way out, you can take your chances and try the Risky way.

The risky way is very simple. Let's use our previous example of the two soundcards and the MIDI interface. If you thought that the Loser soundcard was the problem, instead of removing all the cards or taking an inventory of all the IRQs, Port Addresses, and DMAs in your system, you could simply change some settings.

Let's say you weren't able to record MIDI using the Loser soundcard, and since not being able to record MIDI is indicative of an IRQ conflict, you could change the Loser soundcard's IRQ setting to one that you thought was free. If you guess correctly and change it to an IRQ that is free then you're successful at the risky way: You have nothing more to do. BUT...if you fail you can open yourself up to potentially more nightmarish problems—like your computer not booting into Windows which makes it much more difficult to change a setting. You must decide: The safe way or the risky way? We, of course, recommend the safe way.

Back to index of technical articles