Do you remember?
Twenty years ago, the Fluke 9000 series Micro-system Troubleshooter line offered an asynchronous signature probe option. With this option, engineers could pinpoint every digital hardware fault on a board, including faults in circuits that operated independently of the microprocessor bus cycle. Engineers could test boards with this system''s built-in, preprogrammed test routines. Users could automatically check the entire microprocessor kernel—bus, ROM, RAM and I/O. The probe option also eliminated the need for a logic analyzer or scope to test asynchronous circuits.
The system installed into a new or existing 9000 series unit, and offered signature analysis, waveform capture and event counting. The 9000 could diagnose DMA controllers, disk controllers, communication circuits, peripheral controllers and dynamic RAM timing relationships.
That was then
In its May 1969 issue, Broadcast Engineering ran an article called "FM Proof of Performance." This article sought to answer the question of why FM is better and how to prove that it''s better so engineers will actually use it. At the time, all FM stations were required to make a standard monaural proof. If a station also broadcast part of the time in stereo it had to run an additional stereo proof. The “system approach” emerged—measurement from mic terminals input to transmitter output.
This picture, from the cover of the May 1969 issue of Broadcast Engineering, shows Patrick Finnegan as he performs a proof-of-performance test. Broadcast Engineering began a three-part series on radio station proof of performance measurements in response to the increasing number of violations cited by the FCC.