Oldies but goodies. (Letters).

What is reported in "Loony Tunes: Bugs blare in software set to music" (SN: 11/30/02, p. 339) is a new application of an old idea. In the 1950s and early 1960s, engineers would check a computer by setting a radio beside the central processing unit to pick up the electromagnetic signals put out by switching vacuum tubes and, later, transistors. By programming so that the switching played a familiar tune, the engineer could detect instantly where bugs were. Some of us from those years can recall standing around a $6 million computer listening to it play "Rudolph the Red-nosed Reindeer" for a Christmas party at Cape Canaveral.

WAYNE MCCOY, POOLESVILLE, MD.

I worked for Control Data Corp. from 1962 to 1964. I distinctly remember being impressed by a snappy version of a polka that the programmers used to quickly isolate defective cards plugged into the first mainframe computers. This was done by tuning a portable radio near the frame.

JOHN D. SHOTZBARGER, MINNEAPOLIS, MINN.