• "Unexepectedly quit" error at startup
• Window correctly remembers position
• Toolbar remembers configuration

Why doesn't MacStumbler detect my closed network?

MacStumbler works by sending out probe requests and listening for access points to respond. Closed networks by definition don't respond to these types of requests.

Other wireless auditing programs can detect closed networks by putting the card into monitor mode and sniffing raw 802.11 frames. When legitimate clients try to associate with the closed access point, the SSID can be sniffed. Currently there is no known way to enable this type of monitor mode on Apple's driver, so it can't be incorporated into MacStumbler.

Will MacStumbler ever be able to crack WEP keys?

Cracking WEP keys (a la airsnort) also requires the card to be put into monitor mode (see above).

Will there ever be a version for OS 9?

Probably not. I don't have any experience developing on OS 9 and I'm not really inclined to learn now since I mainly use OS X. However there is another program called ClassicStumbler that you can try.

What are those number fields for beside the colors in preferences?

They're thresholds. Any number above the strong threshold will have the strong color. Below that but above the medium threshold will get the medium color, and everything else gets the weak color.

For wardriving, MacStumbler requires a NMEA compatible gps device, which means your gps must have a serial connection and you will need a USB to serial adapter since (AFAIK) no macs that still have serial ports support an airport card. MacStumbler requires the NMEA interface to be set to 4800 baud 8 data bits 1 stop bit no parity (8n1).

Personally, I use a Garmin eTrex unit. It's garmin's basic no frills unit, not a lot of functions besides basic waypoints and route tracking. You should be able to pick one up for about $100. You'll also need a data cable for it, which run about $25. Finally, I use a keyspan usb to serial adapter. I've tried a couple other adapters and found that keyspan generally has the best drivers. With other units the drivers would often cause a kernel panic or a crash if the cable was unplugged while macstumbler (or any other serial program) was still using the device. Keyspan adapters are a little more expensive (around $50) but I think it's worth it because their drivers will play nice with your system.

Also, A friend of mine is selling these really cool vinyl wardriver decals, visit his site and pick up a couple for your car or laptop. They look like this:

MacStumbler only works with airport wireless cards, it does not (yet) work with any PCMCIA or USB wireless devices. Apple hasn't provide any information on interfacing with their airport card driver, so I had to reverse engineer the functions required to actually preform the scans. If you're looking for information about how to do the same you can download Apple80211.h. (Last Updated 6/3/02) In addition to submitting numerous parts of the header file, ragge has created an awesome command-line tool for accessing the airport driver.