Introduction
Plug-and-play, or PnP, is a system built into newer systems so that it is possible to install devices built for it with ease. All the settings, like IRQs and drivers, are taken care of so that, theoretically, you can have your new hardware working for you in a couple minutes.
The Macintosh had PnP before the PC did. It wasn't till 1993 it began to take part in the PC world. Four companies took part in this promotion: Microsoft promised
a new Operating System that could take advantage of PnP, Intel promised PnP chips, Phoenix promised the BIOS, and Compaq decided to build the computer. It was realized that PnP could me a real money maker. Installation and configuration could be a real breeze, and there would be fewer calls to tech support, and hopefully, people would buy more parts because they weren't daunted by the chore of putting it in.
In an ideal world, when you plug in a PnP device, Windows 95 will detect the new hardware, adjust the settings, and install the drivers. Many call it "Plug and Pray"
because it is rather moody, but the technology has improved greatly, and most installations are now hassle free.
Making it Work
Not all systems can handle PnP. You must have a PnP operating system, such as Windows 95. Previous versions of Windows can't handle it. Your hardware must be rated for PnP, and you need 32-bit drivers for the device...not to worry though...
they come with it. And lastly, your BIOS must be compliant with PnP.
All of these are easy to get, except BIOS. If your system does not already have PnP BIOS, you will need to replace your BIOS, or just upgrade to a new motherboard. All newer computers, 1995 or later, have PnP BIOS installed already.
How it Ticks
A PnP system scans the entire system for new hardware every time the system is booted. It also determines what every device needs, and makes sure it gets it.
First, though, it scans for legacy devices, or non-PnP devices. These devices can't change their settings and have fixed requirements, so the system must first find these, then configure the other PnP devices around them. Although Windows 95 can't automatically adjust a legacy device's settings, it can often recognize it during install. Windows 95 has many legacy device drivers built into it. Old hardware will work under 95. If it will work under Windows 3.x, it will almost certainly work with 95.
HELP!
Plug-and-play doesn't always work. Whether you have all PnP hardware or a mixture of PnP and legacy devices, PnP can be rather hit and miss.
One common reason for problems is that the system is choosing settings taken by a legacy device. A PnP system has no adjustment abilities when it comes to a legacy device. The more legacy devices you have, the more problems you will have with PnP.
Another reason is the broad array of systems out there. Every system is different, with old drivers, old BIOS, off-brand hardware, you name it. There is no way manufacturers
can design hardware for every possibility.
PnP problems are on the decline though as companies iron out problems as they learn. PnP hardware is getting more and more user-friendly.
The Wizard
Sometimes Windows just won't detect your new hardware when you boot it up. In this case, you just have to tell it to look for it. You do this in Add New Hardware Wizard in the Control Panel of Windows 95.
Just follow the on-screen instructions. When it asked you if it can scan for new hardware, select yes(recommended). It will tell you that it might take a few minutes. Fine. Click next. It will search. If it finds it, it'll display it in a box. If it correctly identified the hardware, click Finish, and it will install the drivers. If it can't find it, it will ask you to manually install it. Click Next. It will give you a big list of devices. Try to find yours on the list, select it, and click Finish. If it's not there, and you have a disk with the software on it, click Have Disk, and do it that way.
All the Rest
In order to avoid trouble, it is best to make sure that all PnP hardware that you buy has a manual override to it, so that it has legacy capability. The best ones have a set of jumpers -- the plastic bridges are automatically set to the PnP setting. But, if you move the bridges, you take it out of PnP mode, and it turns into a legacy. Follow the jumper diagram in the manual to adjust settings manually.
Also, go into your Device Manager every so often and delete old and unused drivers. When you install new hardware and replace old stuff, Windows 95 has a habit of leaving the old drivers there, and this invariably slows the entire system down. Make sure you don't delete the CD-ROM drivers or mouse drivers.
Also, it is best to buy PnP hardware from major manufacturers. Keep the drivers up-to-date. Software such as CyberMedia's Oil Change help keep you drivers up-to-date by checking the internet for new drivers. A free trial of Oil Change is available
at the CyberMedia web site.