Leon Borre Zaccaria Memory Test Images

Pictures of Zaccaria memory signals.

Here are some oscilloscope pictures of the signals you find on the memory chips when turning round on the memory test.

You can provoque a "bad" memory test when you lift a data pin of the memory..and you will of course also turn round and round on the memory test when you have a bad memory chip..

All the signals ar made at a scope frequency of 20msec per division...

The selection pins 1 to 7 are various signals not a lot to learn here.. i show here pin 1 , 7 ,16 and 17 as examples.

Selection signals..

Pin 1

Pin 7 a lot more impulses than 1

Pin 16 very few impulses here, the reason why we cannot measure anything using a universal volt meter..

Pin 17

Data signals

One of the data pins (11/12/13/14) they are all the same The goups of pulses you see ( 5 groups here) are the AA's and the 55's written into and read-out from the memory..

Select and R/W signals

Select signal at pin 8

R/W at pin 10

Furthermore i took a picture of pin 8 (select) and pin 10 Read /Write at a scope frequency of 2 msec per division You see clearly that there are two select impulses for 1 R/W pulse . One selection is during Write ( low = 1 pulse at R/W) and one during Read( high = no pulse at R/W )

two times "select"

Only one pulse on R/W . Using the same scoop settings as above.

The pulse is during Write