The DRAM chips are widely used in Commodore 64, Apple II, Macintosh 128k, Macintosh 512k.

If the setting is on 4164-256 it is possible to select the type of memory (from 4164,41256,4532-L,4532-H) by briefly pressing the select / start key. (memory 4116 has no selections)
To start the test, keep the select / start key pressed for 1 sec.
After the test the result will be displayed, if there is an error the test will stop and the point of the error will be shown.

I made these tester myself for my own and now selling the surplus.