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
Now, let's assume you have booted MS-DOS without any device drivers, and used MSD to test for free IRQs and ports. Next, let's assume you loaded EMM386.EXE with the RAM and FRAME= options to test for free memory segments (if, indeed, your network card needs them) -- and then removed these options after testing. Then, you either physically set the jumpers on your network cards, or ran the setup program that came with the cards in order to configure them. Finally, we've paid attention to the Rules in terms of wiring, and installed cabling as per the previous articles. What next? Testing!
Many LAN adapter cards come with a diagnostic program -- sometimes, the same program as the one which makes settings. Generally, there are two kinds of diagnostics to perform. The first kind will test the card internally. It doesn't know that the card is connected to anything. It will generally return a pass/fail based on the electronics on the card itself.
The second kind of test is the acid test. Can each card "see" the other cards on the network? With luck, your Ethernet card will have a diagnostic that will send test signals and/or receive them. Run this diagnostic on all cards on your network, then look to see if each one reports the existance of all other cards. For this purpose, run MS-DOS on your file-server computer, and test it just like a workstation.
If you've followed all the suggestions in this series up to now, it's a pretty good bet that the answer will be "yes" here. If not, try switching the cards around -- changing the settings as appropriate. Does the problem follow a card, or stay with a particular computer? If it's always the same computer involved, you probably have a conflict in settings with this computer, or an incompatibility with this computer's design. Try some different settings until the card works.
THere are two problems with a LAN which will tend to rear up and bite you. As I mentioned earlier in the series, bad wiring -- especially, improper connections with shorts, or improper terminators, or violation of the wiring rules -- is the number one problem area. The second big problem is setting the Ethernet cards to configurations which conflict with the computer in which they are located. If you can solve these two problems, you are sitting very pretty, indeed!
The next question I often hear is, "What kind of computers should I buy? Should I get a computer sold as a 'file server'?" The answer is, well, sometimes that's counter-productive. If you want to be super-safe, buy a file-server that's labled as such. To be ultra-conservative, buy one with Novell's approval -- they test and "certify" those computers that run correctly. But, nowadays, that's not entirely necessary, especially for the small installation.
The critical question you need to answer is -- what am I going to want to share? The number-one answer is "Disk drives"; number two is "Printers". (CD-ROMs are a third answer heard more often; but they're getting so cheap, why not put one into each PC workstation?) The flip side of this question is "how much" -- how big a hard disk? How many hard disks? How many printers? Think ahead -- think generous -- and double your estimates -- and double them again!
If you anticipate no more than two hard drives in the server, and no more than 512MB of space required for each, then you can do it on the cheap. Just about ANY computer will work as a file server. It doesn't even have to be particularly fast -- I personally ran a 35-user network off a 386 DX-25, with no cache memory, and 8MB of main RAM. This setup seems almost too obsolete to consider for any workstation use today; I had power-users beating it to death with fairly good performance. Certainly, a 486 DX-66 with 256K of cache memory and 16MB of main memory will do excellently!
What if you need more disk space, or want to put one or more CD-ROM drives on the server? You need two things. First, you will need a SCSI interface card. I happen to like Adaptec, but Future Domain is a well-known name, too. A SCSI card permits you to add more than two hard disk drives (including CD-ROM drives, with special additional software).
The second thing you will need is more memory, which implies an EISA-based motherboard. "HUH?" sez you, "Where does THAT come from?" Simple. Novell recommends -- and you really should pay attention to this -- that you install 16MB of server RAM for every 1GB of disk space (1GB == 1024MB), as a rough rule-of-thumb. If you need more than two, 512-MB drives, you are exceeding the 1GB figure, and you need more than 16MB of memory -- maybe 32MB, maybe more -- how much disk space are you going to need a year from now?
ISA 486DX motherboards -- that is, good 'ole AT clones -- almost always are limited to 32MB of RAM. You just can't add any more, period. Moreover, you require special NetWare commands to enable the use of the RAM over 16MB. And, I have seen some really flakey operation of the memory between 16MB and 32MB. It really depends on the quality and reliability of the motherboard's design. Therefore, if you need more than 1GB of disk space -- more than 16MB of RAM -- then you need to consider the alternatives; more than 2GB of disk space -- that is, more than 32MB of RAM -- and you MUST chose something else.
EISA motherboards solve this problem. They use funny, deep slots, which can hold standard ISA cards, or EISA cards. These motherboards usually start at 64MB in terms of memory capacity, and some go up to 256MB of RAM (you don't have to start with that much!). They have two advantages: they will accept more than 16MB -- and more than 32MB -- of RAM without a hitch, and NetWare will automatically make full use of the RAM.
There's an additional advantage: if you buy all EISA cards for your system, you can install them with the EISA setup program which comes with the computer. This program guarantees that you set up all the jumpers for all the cards properly, and prevents you from making a conflict. This trick alone can save you a lot of headaches in installing your network cards (along with disk controller cards). Incidentally, this trick will reportedly be in the next major version of Windows, to be called "Plug-and-Play".
In selecting your server hardware, you don't have to worry about things you generally would worry about for a workstation PC. For instance, why install a color VGA adapter and monitor? A monochrome adapter and monitor will do just fine, saving you $200 or more. Dual floppys are useless -- just get a single 3-1/2" drive. Any old cheap keyboard is just fine. The only things to splurge on are the Ethernet card and the I/O card.
For I/O, just keep in mind, you need enough printer ports to support all your printers. If you can place the printers within 12 feet of the server -- often very easy in a small installation -- then go parallel. You can install up to three parallel ports on a standard PC, which means up to three printers. A monochrome display card often has a parallel port built in; all standard I/O cards also have at least one parallel port. The cheapest way to get another one is to get another I/O card and set the jumpers to disable everything on the card except the parallel port -- be sure it has jumper settings which do this, and instructions which tell you how.
Six Easy Lessons
Here's how to set up a simple network in your small office.
