lights on a computer, esp. a {dinosaur}. Derives from the
last word of the famous blackletter-Gothic sign in mangled
pseudo-German that once graced about half the computer rooms in the
English-speaking world. One version ran in its entirety as
follows:

ACHTUNG! ALLES LOOKENSPEEPERS! Das
computermachine ist nicht fuer gefingerpoken und mittengrabben.
Ist easy schnappen der springenwerk, blowenfusen und poppencorken
mit spitzensparken. Ist nicht fuer gewerken bei das dumpkopfen.
Das rubbernecken sichtseeren keepen das cotten-pickenen hans in
das pockets muss; relaxen und watchen das blinkenlichten.

This silliness dates back at least as far as 1959 at Stanford
University and had already gone international by the early 1960s,
when it was reported at London University's ATLAS computing site.
There are several variants of it in circulation, some of which
actually do end with the word `blinkenlights'.

In an amusing example of turnabout-is-fair-play, German hackers
have developed their own versions of the blinkenlights poster in
fractured English, one of which is reproduced here:

ATTENTION

This room is fullfilled mit special electronische equippment.
Fingergrabbing and pressing the cnoeppkes from the computers is
allowed for die experts only! So all the "lefthanders" stay away
and do not disturben the brainstorming von here working
intelligencies. Otherwise you will be out thrown and kicked