The Emma Codelock project started when Lysator moved to it's new house, the Q-house, during the summer 92. Previously Lysator had been housed in the basement of the B-house at the university. The need for security had not been very great, since you had to gain entrance to the B-house in order to find Lysator. The codelock used then had in it's best days used a 4 number code, during the last years randomly hitting it's keys for a couple of minutes had been sufficient to enter.
Some members proposed that we should buy a normal magnetic-card lock, but I thought that it would be a mess having to bookkeep all those cards. And since we already had a security system, the loginnames and passwords used on our UNIX system, I thoght it would be better if we could use that as a basis for the physical security too.
The lock is based on a single board computer, called Emma, donated (and developed) by ISY (an institution at the university). The Emma is based on a 68008 and contains ram, rom with debugger tools, serial ports and a wire wrap area. To that we added a few buffers to make it talk to a LCD display and three membrane keyboards (with enough keys to get an almost normal QWERTY layout). Suprinsingly the display is still functioning eventhough it has suffered -15 degrees.
All software is written in C, and apart from the routines that control the LCD display and keyboard it contains a crypt routine. The passwd database is simply dumped into the program when compiling.
There is certainly room for improvement on the software side (and some members seem to think the keyboards need improvements too). Currently not much is happening though, if anyone wants to give it a shot contact me or grubba.
Mattias Wingstedt (wing@lysator.liu.se)