read/write section: include oscilloscope images

content/blog/DRAFT-2022-05-26-home-built-computation/index.md

@@ -138,6 +138,18 @@ so we can write a bit by pulsing the drive wire either CW or CCW, and then read
 by forcing the device back to '0' with a CCW pulse. this is a "destructive" read, because
 it destroys the state of the device, but it's still a way to store data across time.
 
+![](1ohm7n_drive_0ohm7n_sense_change.jpg)
+
+![](1ohm7n_drive_0ohm7n_sense_no_change.jpg)
+
+the above oscilloscope images show these two scenarios respectively. we apply a CCW pulse to the drive wire (yellow line)
+and then monitor the voltage across the sense wire (purple line), loaded with a very low-value resistor.
+
+there's always some residual output onto the sense wire -- via inductance from the drive wire if nothing else --
+but the output during a 1 -> 0 state transition (top plot) shows substantially more energy than the 0 -> 0 case (bottom plot).
+
+if we were using these as memory in a core memory array, we could place a capacitor across the sense wire, connect that to a comparator (opamp),
+and recover a clean binary signal from this.
 
 ## TODO: show illustrations of basic logic gates
 - include simulation results