Rex Baldazo
Windows 95 brings together a variety of components to make installing new peripherals in a PC as easy as upgrading a Mac. But tests of several new Plug and Play (PnP) devices show that unless you have all the required pieces in your PC, you can expect to do a lot of work before you get to play.
Various pieces of the PnP puzzle were available prior to the release of Windows 95 (see "Transforming the PC: Plug and Play" in the September 1994 BYTE). But the piece that pulls it all together is a PnP OS. Thanks to the arrival of Windows 95, the promise of PnP on the PC has at last become a reality -- sometimes.
BYTE tested several new PnP devices, legacy SCSI and network adapters, and a new uninterruptible power supply (UPS). To evaluate how the new devices wil
l fare in the typical office containing older PCs, we tested them on legacy computers that don't have a PnP BIOS. Our tests show that if you have a variety of legacy equipment, you may need to pray before you play.
One peripheral that we tested, the American Power Conversion BackUPS Pro 650 UPS from APC (West Kingston, RI, (401) 789-5735), highlighted the benefits of PnP when it works, as well as the frustrations that you can expect when it doesn't. When PnP worked, configuring the BackUPS Pro was a breeze. We plugged in the AC cord, connected the serial cable to our PC, turned on the UPS, and rebooted the PC. Windows 95 detected the presence of the new UPS and presented a dialog box (
see the screen
).
If we had loaded the Windows 95 installation CD into the PC's CD-ROM drive, the process would have been even smoother. The dialog box would not have appeared; instead, the APC software would have been installed directly from the Windows 95 CD. Regardless, once the APC software was
installed, we didn't have to tell the software which serial port to use, set the data transfer rate, or perform any of the other operations that add-ing UPSes has traditionally required.
This magic involves a handshake between Windows 95 and the APC UPS. During boot-up, Windows 95 sends out a query on the serial port. The APC UPS responds with a message that includes the product's name and serial number. If Windows 95 doesn't recognize the device from its hardware list, it then begins the installation process described above.
The APC UPS/Windows 95 combination worked fine on an old no-name clone PC, but it didn't work on a much-newer Zeos Pantera. Neither system had a PnP BIOS, but both should have been able to complete the auto-detection and automatic software installation. Nothing we tried could get the Zeos/Windows 95/APC combination to work automatically. We finally resorted to a manual installation, using the Add Hardware applet in the Control Panel.
Adding a UPS isn't too difficult a
process, since it's an external peripheral. Where PnP is really supposed to help is when you add an internal card, as well as after you've installed it; you can reconfigure PnP cards without having to reopen your computer.
To test this capability, we first tried an EtherEZ 10Base-T network adapter from Standard Microsystems Corp. (SMC, Hauppauge, NY, (800) 762-4968). This time we installed the Windows 95 CD before putting in the card. When we rebooted, the PC detected the new adapter and installed the software from the CD without any additional intervention on our part.
But unfortunately, the computer had previously been using a non-PnP NE2000-compatible adapter. Because this older adapter wasn't a PnP device, Windows 95 still loaded its driver, even though the card was no longer installed. The Windows 95 Device Manager indicated an error in using the NE2000-compatible device, but the Microsoft Networking log-in did not; it simply said that no domains were available.
From the Device Manager,
it was a relatively simple matter to remove the NE2000 device. Even so, after we plugged in the PnP network adapter, it took an awful lot of configuring and rebooting before we got it to work.
Our only true success story was with the Future Domain (Irvine, CA, (714) 253-0400) PNP-1640 SCSI controller (
see the screen
). The PC initially detected the new card much as it did the APC UPS and the SMC EtherEZ. But even better, whenever we removed the Future Domain card and then rebooted the PC, the device driver did not load, and no entry appeared in the Device Manager.
Note that our mouse, which was not a PnP device, showed an error because it was not plugged into the serial port. If the mouse had been PnP compatible, Windows 95 wouldn't have loaded the driver at all.
PnP promises a better future for those who want to upgrade their PCs. But as our experience illustrates, PnP works best when everything -- the BIOS, the OS, all the attached devices, and your applications -- are
PnP compatible. This is welcome news for vendors who want to sell new PnP products, but not such great news for system administrators. For those without a PnP BIOS, the combination of Windows 95 and PnP devices still brings benefits. But adding new devices is still not without some pain, and the experience is rarely as simple as plugging something in and turning it on.
screen_link (28 Kbytes)
When we installed APC's UPS, Windows 95 detected the new device and presented this dialog box, which prompted us to install software from a floppy disk. If we had loaded the Windows 95 installation CD into the PC's CD-R
OM drive, this dialog box would not have appeared; instead, the APC software would have installed directly from the Windows 95 CD.
screen_link (25 Kbytes)
When we installed a Future Domain SCSI controller, the PC recognized the device automatically. Even better, the PC performed properly after we removed the SCSI controller.
We Plugged, but They Didn't All Play
