Siemens SICOMP M80 frontpanel

SICOMP M80 frontpanel, large shot

The writing next to the LEDs reads, from left to right:

PowerStopProcessor checkMemory check Console checkBootstrap checkPower supply check Power supply
Upon booting the microprogram is loaded, then some CPU tests are done. If the system was brought down by force, i.e. major power outage, first the CPU commands are checked, then RAM, PROM, memory, cache, test if a console is attached, and then check for the bootstrap code. During this process, the according LEDs light up if the tests succeed.

(by the way: strange standarts.. 300 Bauds, 8 bits, odd parity, 1 or 2 stop bits for doing basic hardware checks using a video terminal...)