Hello Steven,

The item in your picture (http://www.maxcode.com/crap/blockthingy.jpg) is a delay line. The markings on the top - VCC is where 5VDC is hooked up, G is where ground is hooked up, In is where the signal input would be, Out is where the finial signal come out, 1, 2, 3, 4 are the amount of time the signal is delayed in microseconds. The device is used with Dynamic RAM (the main memory of your computer) to provide a required delay between two signals called CAS (column address strobe) and RAS (row address strobe). The Z80 microcomputer incorporated this timing into it artecture which was quite revolunary for it time.

Regards,

Charles Bannister