Installing an HP ScanJet under Windows NT

Getting a scanner to work with NT is easier when you follow these shortcuts

Scanners are important hardware items for many Windows NT sites, butgetting a scanner to work under NT can be a challenge. To do so, you need anNT-compatible scanner, a SCSI host adapter, and the right drivers. After severaltries, I finally got my Hewlett-Packard (HP) ScanJet desktop scanner up andrunning under Windows NT 3.51 and 4.0 (for more information about my hardwaresetup, see "Author's System Configuration," page 137). Here, I explainthe procedure I used to install my scanner and provide tips you can apply torunning flatbed scanners (or other types of image scanners) in your NT shop.

Windows NT Compatibility
Flatbed scanners are scanners that have a flat glass surface on which youplace the object you want scanned. A reading head moves across the surface toinput information.

Currently, HP ScanJet scanners are the only flatbed scanners that Microsoftofficially supports (i.e., includes on the Hardware Compatibility List--HCL) forWindows NT versions 3.51 and 4.0. However, several other flatbed scanners rununder NT 3.51 or 4.0, including Epson, Microtek, Xerox, and UMAX scanners.According to users of these scanners, the manufacturers have developed theappropriate drivers, making their installation under NT 3.51 and NT 4.0 fairlystraightforward.

SCSI Interface
To attach a scanner to an NT system, you first need a cable and a SCSIinterface, or host adapter. (You can't use a parallel port with NT. Forexplanations of SCSI and other terms in this article, see "Glossary,"page 134.) Although some motherboards include a built-in SCSI bus, most SCSIinterfaces take the form of a card that you insert into a spare expansion slot.Microsoft has certified more than 100 SCSI adapters as compatible with NT 3.51and 4.0, among them are products from Adaptec, BusLogic, and NCR. Again, checkthe HCL for a complete list of supported SCSI adapters.

The Right Drivers
A driver is a program that controls a piece of hardware and lets itexchange data with other hardware and software. A SCSI scanner usually needs twodrivers to work, or more likely, two sets of modular drivers and theirassociated DLLs and system files. The host adapter driver is often called thesystem-level driver; the scanner driver is usually called the sourcedriver. Make sure you have the latest versions of all required drivers.

Driver compatibility is a problem in the NT environment. For example, thehost adapter needs the correct driver to communicate with NT, the scanner needsa driver to talk to the host adapter and to NT, and the drivers must worktogether. In NT 3.51 and 4.0, Microsoft provides two HP ScanJet scanner driverssimilar to the original HP drivers. (Microsoft's developers customized theoriginal drivers for NT.) You'll want to use these Microsoft drivers, ratherthan the original HP drivers, to ensure that your HP ScanJet scanner works handin hand with NT.

To further complicate matters, scanner application programs often havemodules to communicate with the scanner via the operating system and the hostadapter. Two main industry standards exist for image and scanner interfaces:Image and Scanner Industry Standard (ISIS) and TWAIN. Many software developersand scanner manufacturers have designed their application software, scanners,and drivers to comply with one or both standards. TWAIN is more common than ISISfor scanning products that work with NT. ISIS is more commonly used foroptical character recognition (OCR) packages. For example, Adobe's Photoshop andPictronics' IntelliScan (an image-scanning and editing package) are TWAINcompliant. Pictronics claims its product supports all desktop scanners throughthe TWAIN interface on NT. Be aware, however, that not all TWAIN software workswith NT; as mentioned earlier, you need the latest drivers. For example onlyTWAIN 1.6-compliant programs, which include TWAIN_32 drivers (not the olderTWAIN32 modules), work with NT 3.51 and 4.0. Thus, Adobe Photoshop 3.0.5, whichuses the TWAIN_32 drivers, works with NT; however, version 3.0 doesn't workbecause it uses the TWAIN32 drivers.

Connecting an HP ScanJet Scanner
Connecting an HP ScanJet scanner to an NT 3.51 or 4.0 workstation requirestwo main steps: installing the SCSI adapter (and its drivers) in the workstationand verifying that it communicates with NT, and loading the scanner applicationsoftware on the workstation. According to the HCL, you can run HP ScanJet II, 3,and 4 series scanners with NT.

In theory, you can use either HP's simple 8-bit ISA SCSI card(C2502-66500), which works only with HP scanners (although it can work withother SCSI cards), or a third-party SCSI card. (For detailed instructions aboutinstalling the HP SCSI adapter driver under NT, see "Configuring the HPSCSI Adapter.")

Once you've installed the SCSI card and loaded the drivers, NT and the SCSIcard can talk to each other. However, with the HP SCSI card, users often get anerror message when they reboot--as I did--stating that one or more of theservices did not launch correctly. The problem is simple: NT fails to see the HPSCSI card.

The solution I found is equally simple: Buy a better SCSI card. (I used anAdaptec 2920 card.) If your HP SCSI card doesn't work under NT or you have otherSCSI devices and want to use a single adapter for all your peripherals, replacethe HP card with a SCSI adapter from another vendor.

Once I installed the Adaptec card, I reloaded NT 3.51 and NT 4.0. Bothversions of the operating system detected the card.

NT 3.51 predated the new card. As a result, the installation routineidentified the card's chipsets and firmware but not the model.

In contrast, NT 4.0 identified the exact model and loaded the appropriateAdvanced SCSI Programming Interface (ASPI) drivers. (The latest version of theHCL includes the Adaptec 2920 card.)

Adding HP DeskScan II 2.2
HP has two scanner programs: HP DeskScan II versions 2.2 and 2.3.Microsoft's documentation states that Microsoft currently supports only HPDeskScan II 2.2, a 16-bit Windows 3.1 program, under NT 3.51 and 4.0. HPprovides a patch with HP DeskScan II 2.3 that lets it work with NT. (Isuccessfully installed both HP DeskScan II versions; for installationinstructions, see "Installing HP DeskScan II 2.3.")

To run HP DeskScan II 2.2 under Windows NT, you must first verify that NThas loaded the following two modules:

The previous process configures NT to run HP DeskScan II. You need thefirst step because HP DeskScan II is a 16-bit program. NT runs 16-bit packageswithin a virtual DOS machine, and you can set up each program with its ownvirtual equivalent of the DOS/Windows 3.x config.sys file. In NT, thisconfiguration file is called config.nt, and you can set up individual config.ntfiles for each package. The DEVICE= line in the config.nt file tells NT to loadthe driver hpscan16.sys whenever the user starts up HP DeskScan II.

In a DOS/Windows environment, HP DeskScan II performs commands through a16-bit device driver (hpscan). However, a device driver cannot operate in thisway under NT because NT's 32-bit environment doesn't support this 16-bit driver.To work around this problem, hpscan16.sys and hpscan32.dll create an alternativedriver that works in NT's 32-bit environment. However, HP DeskScan II stillthinks it's working with a 16-bit driver and operating system. Because HPDeskScan II 2.3 is a 32-bit program, it works better with NT than HP DeskScan II2.2, but it still needs a bit of tinkering to work with NT 3.51 and NT 4.0, asyou can see in "Installing HP DeskScan II 2.3."

As you've seen, HP ScanJet scanners can work with NT 3.51 and 4.0.You can run other scanners under NT, too--for more information about scannerproducts as well as SCSI adapters and users' experiences with the products,check out the online sites listed in "Online Information Sources."