To correctly test network, you must have modified some files to suit your configuration.
We will call SOURCE the machine running hwtest, DESTINATION the other. Of course, SOURCE must have a recognized ethernet card installed; in case it is a CardBus one, it must be already inserted in SOURCE at program start - no hotplug available -.

CONFIGURATION SETUP
- First of all, I assume that you are working on private addresses, say 10.0.0.x or 192.168.1.x; if you are connected to Internet you could have public addresses around. If you don't know how to deal with them, I suggest you disconnect from the Internet and work in your home LAN. To keep things simple it's best to have the network composed only by SOURCE and DESTINATION (using a hub or a crossover cable, doesn't matter).
- Make sure that TCP/IP is correctly set up on DESTINATION machine operating system: if you can exchange files, share resources, you are OK. You have to disable firewalls and DHCP if present (Win XP generally uses it by default), because you need a configuration with static IP addresses.
- Get (for example with WinIPcfg or ipconfig) MAC address of both computers and IP address of DESTINATION. You can choose any IP address for SOURCE which can be seen by DESTINATION (it depends on network mask; generally it is 255.255.255.0 and the two IP differ only for the last octet)
- In IP.asm: 
change the address at .destMAC: to DESTINATION MAC;
the second line at .stack_ip: to DESTINATION IP.
You can leave the SOURCE IP in the first line as it is or choose another address.
After making changes, you can compile and launch HwTest
- In arpping.bat: after arp - s, put your SOURCE IP and MAC addresses; after ping, put your SOURCE IP address.
- if DESTINATION is running Windows, place UDP.exe and arpping.bat there, and run UDP.exe BEFORE selecting the video mode at the start of HwTest in SOURCE.

Notes for Linux users on DESTINATION machine:
- I had to insert SOURCE ip address in /etc/hosts
- ping and arp commands are those found in arpping.bat, provided you substitute "-" with ":" in arp -s command MAC address
- I used UDP.exe with Wine 1.0.1: it sent data out but didn't receive (or at least, didn't show) data in. It's probably a Wine lack which may be fixed in newer versions.

RUNNING TESTS
Right after the program has loaded, an UDP packet is transmitted from SOURCE: UDP.exe window should show "Received nnn bytes from ...".
At the info screen, seek the line starting with "Equipment": after "Data:", you see the first four bytes of the detected card's MAC address. Next, if card driver supports it, comes link status: OK when link is up, KO when it is down.
Any time you want you can ping SOURCE with arpping.bat, or send an UDP packet: choose how many bytes to send, put SOURCE IP in the textbox right to the "Send UDP" button and press it. HwTest will display the last four bytes in hex in place of MAC address (after "Data:").

Thanks to www.fpga4fun.com for UDP.exe.
