Welcome to the 90s! It's a great time to be automating our offices—we have so many choices. More and more, those choices are going to involve networking our offices. Unfortunately, given so many choices, it's sometimes difficult to decide what to do. You may have heard about the capabilities and possibilities in linking your office PCs together. You may have even been reading up on the subject. Many magazines specialize in networking. You may have also found out the limitations of these sources of information. Simply: much of this information is aimed at the networking of an entire office, business, or firm, dealing with hundreds or thousands of PCs.
September 1998
If you are starting this series late—welcome! This is the column devoted to the individual who wants to install a network in the home or in a small business, and wants to do it on the cheap. DIY—Do It Yourself—is possible in networking land. However, the "read-between-the-lines" stuff that you need to know is often missing. This column will fill you in on the real dope on how to design, install, and use your own LAN—Local Area Network. In the past, we thoroughly covered how to install cabling; I recommended Thin EtherNet (possibly in ready-made segments) as the cheapest and easiest way to get started.
First, a newsworthy digression. At Spring Comdex in Atlanta two companies caught my eye. Where do you go to get those little doo-dads you need for networking? Well, when your local Radio Shack and electronic supply house won't do, I found a California importer that carries an amazing variety of bles, connectors, and parts. Call Pi Manufacturing Corp. at 909-598-3718, or write them at 187 S. Brent Circle, Walnut, CA 91789. What really attracted my attention was several unusual BNC "T" connectors, with different shapes guaranteed to get you out of a tight squeeze on the back of your PC. These guys focus on quantity buyers, but they do have pricing for onesies and twosies (at a small premium).
Now, you remember I've been mentioning the AMP Thinnet Tap System, as an ideal jack system for Thin EtherNet—one which makes it impossible, when correctly installed, to accidentally "crash" the network by unconnecting something. I found another company which made a very similar product, with some unique characteristics. Advanced Electronic Support Products (AESP), at 1810 NE 144th St., North Miami, FL 33181, (305) 944-7710, has some unique networking products. They have a line of wall-plates and jack assemblies that do the same thing AMP's system does, with certain advantages.
While the jacks may cost as much or more than AMP's, the drop cables cost considerably less. Also, AESP's system uses BNC connectors for everything. If you are using ready-made Thin EtherNet cables for your trunk, with BNC's already attached to the ends, then AESP's system can be considerably easier to install. And, a system with less wall jacks but more drop cables can also benefit by their system. Finally, since the jacks are standard BNC, you can use regular old-fashioned BNC cables to connect several devices to one jack (without the safety their drop cables provide). On the other hand, an installation with a lot of jacks but fewer computers/drop cables, or one wired from a single piece of EtherNet cable being cut to length, would probably benefit by the easy installation of the AMP system. Isn't it nice to have a choice?
Last month, we investigated the different categories of EtherNet adapters for PCs. We saw that you could buy a card with different combinations of network connectors: BNC, UTP (twisted-pair), and AUI (funny jack for cables going to transceivers). We suggested you buy a card with BNC, or both BNC and UTP ports (called a combo card).
To make an EtherNet card work, we saw that you need to find a free I/O port address (300h usually works fine), and a free interrupt (IRQ 5 usually fits the bill). For fast cards, you may also need to find a free upper memory segment—you can use EMM386.EXE's FRAME option to check an area and see if it is available; C800 is often just great.
Some cards use physical jumpers to install them; others use an installation program to set them up. You can get ISA, EISA, and VESA VL cards; VL is faster than ISA, but make sure you have a bus-master-compatible motherboard!
If you use a card that takes up a memory segment, you'll want to set it up so that the first free memory space available is used—you may have to play around to find one that works. The reason for this is that you want to maximize the leftover contiguous free space, which makes it easier to LOADHI more stuff. Note that you can use the FRAME= parameter in EMM386.EXE to check and see if a proposed location is free of all obstructions in hardware.
There's another factor involved in buying an EtherNet card, and that's its compatibility. There are several families of EtherNet cards that have become very popular, and therefore, something of a standard. The more compatible a card is with a standard, the easier it is to get up-to-date and well-debugged drivers to install. Not only do manufacturers copy their own design features, making their newer cards compatible with their older ones, but also you will find "clone" cards that duplicate these features, too.
The grandfather of EtherNet cards is the 3Com series. Another popular design is the Western Digital, which is now made by SMC. A third big seller is Intel. But the grandfather of popular network cards is ... Novell!
Now, don't get me wrong. Novell does not make hardware. They used to, though. Their original design was the NE-1000, an 8-bit ISA card. A much bigger seller was their later, NE-2000; it featured a 16-bit ISA interface. There were even later variations for MCA-bus computers, and accelerated cards, but the NE-2000 design is probably the most cloned design available. You will find all kinds of little companies selling an NE-2000 clone. Novell themselves, sold off their hardware operation; the genuine article is now made by Eagle/Anthem.
The NE-2000 card is a genuine building-block card. It uses an I/O port and an interrupt. The I/O port is selected from 300, 320, 340, and 360 hex; the interrupt is selected from IRQ 3, 4, 5, or 7. However, newer/clone versions often have additional ports and IRQs to chose from. It's just a matter of picking the ones that don't conflict with anything else.
NE-2000 clones are not the fastest cards, but they are often the easiest to install, and the cheapest. I have seen prices for well under $50 per card. For many purposes, especially the small installation that we are designing, they serve just fine. If you have an intense need, you can look at the accelerated cards, such as the WD/SMC Elite cards. Note, however, that these accelerated cards usually require DMA and/or memory segments, making them more difficult to install. Also note that there is no guarantee that a particular card will work in a particular computer: make sure you can return it if it's a no-go!
In my opinion, it is easiest to work with just one type of network card, used in every computer you have. However, you can often get improvements in speed by installing an accelerated network card in the file server computer alone, and install a less expensive card in the other computers you are connecting together.
Six Easy Lessons
Here's how to set up a simple network in your small office.
