My 'intranet' : Hardware

10-base2 network interface card for your RISC OS computer
from £25 second hand to around £80 new
10-base2 network interface card for your PC
from a pound second hand, to £20 new - any old ISA card will do, but make sure it has a vendor's name on it, and best if bought with drivers/user guide.
10-base2 network cable. Price varies according to quality and length, but you can get a reasonable 5 metre length (with fitted BNC plugs) for around a fiver.
Two T-pieces, and two BNC terminators.
Price varies, estimate a pound each.

However BNC 10-base2 networking is kinda crappy, so why not go a little further and try 10-baseT? It's benefits are more expandable, much more reliable, and if you shop around it doesn't cost that much more. You will need this as the suggested hardware:

10-baseT or combo (BNC/RJ45) network interface card for your RISC OS computer
from £25 second hand to around £100 new; rather more if you want a 10/100 card
I paid £30 for my i-cubed RiscPC combo card.
Combo network interface card for your PC
from a pound second hand, to ~£30 new - a 10mbit card will suffice, however there is little to be lost by getting a 10/100 card; it will talk to your RISC OS computer in slow rate, and other PCs quickly, if you have a switchable hub.
I bought a Kingston ISA card sold-as-seen for three pounds; and a DLink 10/100 PCI card from a charity shop for 50p (the grannies didn't know what it was so asked me for 50p!).
Cat5 10-baseT network cable with RJ45 plugs affixed at each end. Don't try to save money by making your own, it isn't worth it.
Prices vary wildly; I bought a set of cables from a 'junk' auction for a couple of quid.
The cable I use between Aiko and Alyson is a proper 10/100 cable that is crossed over (so two machines can talk back-to-back (no hub)), cost me seven euros in the local supermarket.
If you plan to be making a new network with some high speed parts, go for 10/100 cables from the outset. It will be more reliable that way, and as we're up to "Gigabit" nowadays you'd probably have to go looking to find 10mbit-only cabling!
A hub
Price varies greatly, depending upon ports and features.
If you are on the scrounge or the charity shop run, it may be an idea to keep your eyes open for a switchable 10/100 hub. The crap ones work at "all 100 or all 10", the better ones can cope with ports at different speeds.
For newer equipment, same thing applies, but probably all the hardware will be 10/100; or even gigabit. You might prefer a hub with WiFi capabilities. I'm not getting involved with WiFi at the time...
On the other hub, if you can find a 10mbit(only) hub for a couple of quid, it is worth getting it to get you going. Your network will only run at 10mbit, but it's a start!
I bought my (original) 12 port 10mbit hub sold-as-seen for £5. The later 24 port 10mbit hub cost me £8.

Hub or router?
I believe that the difference is a hub takes packeted data from one port and sends it to other ports. Some (few) are stupid and send out to all, while most try to 'learn' what computer is on each port so it only sends packets to the correct machine. The problem is, the 10mbit bandwidth is 10mbit through the hub. You can't have two 10mbit conversations to different pairs of machines going on simultaneously. Additionally, it may be tricky for 10/100 networking. It may be that everything slows down for a 10mbit communication (even the unrelated 100mbit stuff) and speeds up again for faster comms. Or, worse, the hub will step down to 10mbit and stay there if it 'sees' a slow connection.

Conversely, a router is a much smarter device. Allowing better management, including paritioning, a router will cope with two high speed machines talking at high speed to each other whilst a high speed and low speed pairing talks on different ports.

If my understanding is correct, then obviously the router is the more desirable option, but it comes at a price...

I did quite well really, didn't I? The cost of the RiscPC network card was rather more than the combined cost of all of the other bits of hardware utilised.
How did I do it?
Dead easy. Find a local dealer that specialises in networking contracts. As more and more people are finding a 10mbit network too slow (imagine, five WinME machines trying to pull streaming video from an ISDN link to the Internet!), they are dumping their old hardware and going for faster components. Thus, there are loads of incredible bargains to be had. Certainly, dead cheap network cards for PCs are ten a penny, but a good solid hub going that price!?!?

When this was first written there was no 10mbit network card for RISC OS machines. Now there is. It is quite expensive (not so much by RISC OS terms, but compared to PC kit...); and the worry I have is what spec is required to make best use of it? I suspect it will require an Iyonix to make it fly, and a Kinetic to get much additional benefit. Remember that there is quite a bottleneck with the podule bus and the 'front side bus'. 100mbit/sec is logically the same as 12mbyte/sec. It's an impressive thing to get a harddisc talking to a generic RiscPC at half that, so while you may be able to get better than 10mbit (which is just over 1Mbyte/sec), you probably won't get the full benefits of 100mbit networking. Still, even running a lame quarter speed, that's twice as fast as an old network card could do it!

My advice? Go for 10/100 kit if you can afford it. The more stuff that is 10/100 compatible to begin with, the less that will need to be changed in order to go for a better speed network.

Failing that, stick with a cheap and plentiful 10Mb parts. It isn't breakneck, but for a small home installation it will be plenty (unless you're into streaming media and/or VNC sessions). The 80486DX/4-66MHz machine running Windows for Workgroups 3.11 (with a generic NE2000 driver) served a 1Mb test file to my RiscPC (ARM7 40MHz) via OmniClient's LanManFS (NetBEUI) in a shade over two seconds. My harddisc is only just half that speed. However a benchmark showed a much poorer picture. My harddisc managed 1.26Mb/sec average and the Ethernet managed 430Kb/sec average. The reason? Transferring big chunks of data is a nice fast operation. But transferring lots of little blocks (as the benchmark program did) is tedious and slow and has many overheads. The speed of the network, though, is more likely to be 430Kb/sec instead of >1Mb/sec as application file handling is more likely to do a number of small transfers instead of large ones.

In more recent terms, transferring an application from RISC OS (ARM710 RiscPC) to the PC (450MHz P3) harddisc (for RedSquirrel) copied a number of small files (!Run, !Sprites, etc) and it did it in around three minutes, with a lot of time apparently doing nothing.
Transferring two TAR files (the RISC OS Open sources, after un-bzip2ing), totalling around 140Mb, was achieved in a pleasing six minutes.
It's kinda like a SCSI tar streamer. Little files are clunky and cumbersome, big files can fly...

Click here for a pictoral guide of how easy it is to fit a NIC into a RiscPC.