Looking for a logic comparator

Back in the 80s a company called Bugtrap made a number of logic comparators where you simply plugged in a known-to-be-good part, flipped proper switches for the Vcc and Vgg, and then clipped a glomper plug over the suspect IC and it would indicate if the outputs were different.

The later ones worked for TTL and CMOS, while the first series being separate.

They turn up on eBay regularly and are reasonable in cost, and fairly accurate - as much as any incircuit comparator can be.

These go up to 20 pin devices (74LS244, etc.) and are very handy on the test bench.

There was also the Global version - much the same - but it appears to be rarer...

John :-#)#