We're going to cut out all the "legacy" crap: Token Ring, Banyan Vines, Novell Networks, IBM Universal Networking blah blah blah. We're not using any of that legacy crap. About 97% of the time, with a vintage IBM compatible, we will be using TCP/IP with DHCP over a regular network like a modern PC does. If that's all greek to you, well...then let's begin, shall we?

A LAN - or Local Area Network - is the network inside your home. IE, you have a computer in your den, a computer in your basement, and a vintage computer in your garage, and they all talk to each other, that's called a LAN.

The reason I make the distinction this early on, is because most computers that are networked today are not assigned just ONE, but TWO IP addresses, the Internal IP address and the External IP Address.

An IP Address, in the case of vintage computers it's something we call IpV4 - or Internet Protocol version 4 - is a number assigned to a computer to identify it on the network without using it's MAC address (or "Hardware Address" - more on that in a moment). The number consists of 4 "octets" (4 groups of 3 numbers - 0-254) to identify the PC. Typically, your internal IP will be what we call a "Class C" address - which is typical 192.168.something.something (ie 192.168.1.1 - which would be the IP of your internet router or internet gateway appliance the ISP gives you dpeending on your setup). The external one usually has a different class and has totally different leading octets compared to your internal one. The external IP is how your computer gets into trouble on the internet BTW...that and the MAC Address can be used to target it too. But we'll get to the security part next.

You usually don't have to set the IP Address for your vintage machine. This is through a technology called "Domain Host Control Protocol" or DHCP which leases an IP Address from a address pool (a list of addresses within the class or a "scope" of addresses) to the computer in question, and then "renews" it every so often when the lease is up. Almsot everything we do here is under DHCP. THe alternative is to assign the computer what is called a "static IP" which never changes. So it will be 192.168.xxx.xxx - and it will STAY at those octets filed with XXX's until someone changes the configuration. Static IPs are typically use for internal resources that need to stay consistant such as Servers.

There's also a Subnet Mask which for the scope of this page should almost always be 255.255.255.0 unless you have a pretty fancy setup (ie. the kind of setup that means you are someone who is Network Administrator material). I'm leaving out a lot in this for brievity, and to not bombard you with too much tech stuff.

So how does the PC do all this? Well, there's a few important pieces: Network Interface Card (NIC), Ethernet Cables (Cat5e suffices for vintage machines), a Switch (sometimes built into your router or ISP's gateway, sometimes not - basically a group of ethernet ports), a Packet Driver (specific to your NIC), and software that enables networking, which or DOS would be Mike Brutman's mTCP suite in the case of 90% of what we're doing here.

The NIC for the vintage PC is typically a expansion card (ISA, PCI, PCMCIA Type-II, MCA in our cases here with 8088-80486 machines) that plugs into an expansion slot inside the PC, and has a port sticking out that looks like a giant, old-school, analog PBX/Telephone port - called RJ45 or "ethernet" as most people call it. The cable plugs in just like an old landline cable. Of course, like anything this old-school, you will need to know the IRQ (Interrupt) of your card (usually 2,3,5,7,9,10, or 11), your memory address (usually something like 0xC00 or 0xD00h), and knowing the MAC Address (ie AF:1B:2C:3E:4F:A1:B2:C3) or Hardware Address can be helpful to when troubleshooting this device.

Most of these cards are limited to a maximum speed of 100mbps for PCI devices, and 10mbps for everything else (ISA), because of a limitiation of bus speed due to the speed of the expansion slots in the PC.

Ethernet Cable, anything from Category 4 (really old) to whatever the current Ethernet should work. Cat5e and Cat6e are usually what I use because it's cheap, readily available, and I can make my own at home if I need to (or fix broken cables with a crimper).

For switches, you don't need a big fancy Cisco Managed-type switch, you can get a simple $1-15 special from the local Value Village and it will do the job just as well, evne a 10mbps unit like I have in my garage is fine.