Networking Your Computers

The following article is reprinted from the April 1996 issue of PC Novice magazine. For more information on subscribing to PC Novice, call 1-800-733-3809, or visit the PC Novice home page. (Note, the link to PC Novice is no longer valid and has been removed.)

by Bill Hayes

You don't have to be a rocket scientist to network your home machines. The computer know-how you've already gained can help you find a way to share files and printers between your computers. So whether you can afford a bottle rocket or a starship of a network, there are ways to make your files zoom from one system to another.

Inventory Your Needs

Suppose your friend Euston says to you, "Hey! Network cards are really cheap. A couple of those and some software, I bet we could network your PCs in no time." Well, maybe so, but after your genius friend makes your PCs look as if they're ready for a lunar excursion, you had better be comfortable with the results. Otherwise, your friend is going to get mighty tired of phone calls that start with, "Euston, we have a problem."

Network interface cards and local-area network (LAN) software can take your computers into the networking stratosphere, but this isn't the only solution, especially if terms such as IRQ, I/O ports, and upper-memory areas make you feel like you're breathing in a vacuum. Happily, there are solutions that can match your experience and pocketbook.

First, if you only want to share a printer, there are very inexpensive printer-sharing schemes (see the following article). Likewise, if you?re looking to sling files from one side of the room to the other, there are ways to do that without opening your PC.

It Takes Two

Take stock in your investment in computer equipment and software. If you're planning to link two computers together, you may already have the materials. Beginning with MS-DOS 6.0, IBM and Microsoft put the Interlnk programs called Interlnk.exe and Intersrv.exe in their DOS 6.x releases.

For this to work, you have to have either a serial port (i.e., COM1 or COM2) or a bidirectional printer port available. As the name implies, bidirectional printer ports let data flow in both directions. A relatively recent innovation appearing with the IBM P/2 computers, you won't find bidirectional printer ports as stock items on XT-class computers.

You'll also need a serial cable or a bidirectional printer cable. The serial cable can be either a three-wire serial cable or a seven-wire null modem cable. The bidirectional printer cable is a 25-wire cable with male 25-pin connectors on either end. The standard printer cable won't do, as it has a male 25-pin connector on the PC end and a Centronics connector on the printer side. If you have a choice, the parallel port connection will be faster. The seven-wire null modem serial cable can let you remotely install Interlnk.exe.

One computer will need MS-DOS 6.0 or newer, and the other can be using MS-DOS 3.0 or newer. The INTERLNK and INTERSRV commands will help you set up one of the computers as a file server and the other as a client. You'll need around 16 kilobytes (KB) of memory to load Interlnk.exe on the client and 130KB to load Intersrv.exe on the server. (A file server is generally the biggest, fastest, and most powerful computer on a network; it possesses more storage space and processing power to run the network operating system. Clients are individual computers connected to the server to share its processing power and resources.)

Use a text editor such as Edit.exe for MS-DOS machines to place the line:

device=c:\dos\interlnk.exe

into the Config.sys file. By default, the Interlnk program assigns three drive letters to drives that may be available on the server. If, for example, your server has two diskette drives and two hard drives, add:

/ drives:4

to the end of the INTERLNK command. To start the server, type intersrv at the command prompt.

With the client and server machine started, interlnk will display the drive letter assignments.

The printer assignments may seem confusing initially, but this lets the client route printer output to printer ports on the server machine. This works well when the client is a laptop, and the server has available printer ports.

To change to the server's C: (hard) drive, you log on to the client's F: drive (which appears as a network drive). The redirection of drive letters is common to most PC-based networks. You can treat the redirected drive as if it belongs to the client machine, deleting, copying, or renaming files, and creating or removing directories. While the DOS 6.0 manuals claim you can run programs on the redirected drives, the access speed may make this impractical. You can run batch files to help automate file chores and run them from the server's drives.

Neither Interlnk.exe nor Intersrv.exe work with Windows. If you work in Windows 3.1 or Windows for Workgroups 3.11 (WFW), you'll want to use other products. LapLink for Windows, by Traveling Software, for DOS and Windows PCs supplies the cabling and software to connect two systems for file transfers but doesn't really network your computers (see "Remote Control Software: Extending The Boundaries Of Your Office" in this issue).

Windows 95 Connection

Without spending a penny, Win95 users can add the Direct Cable Connection option to their Start menu, letting them perform the same chores performed by Interlnk. The Direct Cable Connection option works with Win95 features such as the Briefcase utility, which is used to update files between PCs.

To install the Direct Cable Connection option, you'll need a serial null modem cable (which matches the two machines serial connectors so that they can communicate with each other) or a parallel cable. An Extended Capabilities Port (ECP) cable can be used with two machines with ECP parallel ports.

After you've connected both machines, open the Win95 Control Panel on both machines, and perform the following steps for both machines:

1. Select the Add/Remove Programs option.
2. Left-click the Windows Setup tab.
3. Double left-click the Communications entry on the Windows Setup page.
4. Left-click the Direct Cable Connection check box.

Once this option is installed on both computers, use the Start menu to run this utility. You'll use the Direct Cable Connection Wizard to help you configure both machines. You'll be required to set one computer up as a host (server) computer and the other as a guest (client).

Before proceeding, connect both machines with the cable you've chosen. The Direct Cable Connection Wizard will help set up the correct port and tell you if the installation was successful.

DuoNet Plus

Leunig Communications Inc. offers a networking solution for two computers called DuoNet Plus ($129), which includes two 10-foot cables. If you're already using WFW on both machines, you can access shared resources such as files, printers, fax modems, and CD-ROM drives in the same way you'd use them if they used network interface cards.

Windows 3.1 and DOS users can benefit from DuoNet Plus? software, which lets them transfer files and share a single printer.

Three Is Not A Crowd

If you want to connect more than two computers, you may want to use the same networking components used to set up large LANs. But you do have choices here, so you may not need to install additional adapter cards.

There are two models of networking commonly used. In the client/server model, a computer is set aside as a server. It lets other computers use its resources for activities such as file and printer sharing. In the peer-to-peer model, all networked computers can share their resources, such as directories, printers, fax modems, and even CD-ROM drives, with other computers on the network.

If all of your machines use WFW, Win95, or OS/2 Warp Connect, you can set up a peer-to-peer network without spending additional money on software.

If you don't want to add network adapter cards to your PCs, you can use a parallel port pocket network adapter, which are external devices. If you run either WFW or Win95, you can use Net44, another parallel port networking solution from L.C.I. (see sidebar).

If you use Windows 3.1 or DOS, you can network older equipment through a pocket network adapter designed for bidirectional printer ports. Designed originally for portable computers, pocket network adapters have been much more expensive than network adapter cards.

However, Addtron offers a relatively inexpensive Ethernet pocket network adapter for about $100. This adapter uses either coaxial (BNC) cabling or telephone cabling (RJ-45) to daisy-chain the network stations together. The cheapest method is Thin Ethernet, also called 10Base2 or ThinNet, cabling. With Thin Ethernet cabling, you don?t need to have a network hub (which can cost $200 or less). The disadvantage of this method, however, is that if you break the cable in any place, you bring the whole network down. (Ethernet is a networking protocol in which PCs listen for pauses in the digital conversation occuring between computers before they begin to "speak.")

Under Thin Ethernet cabling, the computers are daisy-chained together using a BNC T-connector. The first and last computers must use a resistor called a terminator to mark the ends of the network. These terminators must be in place while the machines are running. A 25-foot BNC cable should cost less than $15. BNC T-connectors and terminators with grounds usually cost less than $9 each.

Pocket network adapters such as the Addtron product have a pass-through parallel port that still lets the printer port communicate with a printer. Don't expect printing to happen as snappily as when the parallel port services only a printer.

Opening Up The Can

Should cash be a concern and you're not frightened of installing a hard drive or an adapter card, you can consider using a network adapter card. This is not necessarily a straightforward undertaking. You should be comfortable with changing I/O ports and IRQ numbers before installing an adapter card.

Kingston Technology's EtheRx LC line of Ethernet adapters offer an inexpensive way to link your computers using Thin Ethernet connectors. The ISA version of this card costs less than $35.

EtheRx cards come with the QStart installation utility, which features mouse support and online help. QStart surveys a machine's hardware settings and suggests which IRQ and I/O Port address to use. It then performs a four-step test to ensure the adapter is running properly.

Personal NetWare & LANtastic

Once you've installed a network card, you'll need to choose LAN software. If you're using WFW, Win95, or OS/2 Warp Connect, you already have the software. If you're running DOS or Windows 3.1, you can choose either Novell's Personal NetWare or ArtiSoft's LANtastic software series.

Both of these network operating systems support hardware ranging from IBM PC vintage to Pentium class computers. Before installing these products, you should be thoroughly comfortable with editing your Config.sys, Autoexec.bat, and Windows System.ini files. You should be prepared to learn arcane terminology and concepts not found outside of networking.

Personal NetWare lets you set up a client/server or peer-to-peer network, or a combination of both. It lets you share files, printers, and CD-ROM drives among two to 240 users. A five-user license should cost less than $270.

Artisoft Simply LANtastic is designed for small offices. Its ease of installation makes it a boon for first-time network users. Single-user Simply LANtastic software-only licenses should cost around $50 each. LANtastic for OS/2 is available for around $100 for a single user. The full-fledged LANtastic 6.0 starter kit with two network cards and Thin Ethernet cabling should cost less than $250.

SUBSCRIBE TO

Personal Computers In Plain English

For Just $29.00

Call 1-800-733-3809