Robie Jr ultrasonic signals

Using the Bitscope on the Robie Jr Ultrasonic control shows these wave forms. Measurements were taken from CN1 at pins 4 and 5 on the OKI M6411b-24 IC.

Signal time ~25 ms

Time between signals ~98 ms

Not sure why the signal is so fuzzy? Is it the 30 year old electrolytic caps? Is the signal similar to an IR signal? When using the logic analyzer I seem to get different packets every time. Will continue pondering...

Robie Jr deeper inspection

Okay, so oscilloscopes are expensive. So I purchased this very intriguing piece of hardware. The Bitscope. Oh yeah, its cool. Can you do microbiology with out a microscope? Nope. So an oscilloscope and a logic analyzer are a must for in-depth tinkering. I've laid out the schematic in Inkscape and begun the slow deconstruction and probing.

7-E055-R1. M6411B-24.

Here's what I have been able to learn currently.
LB1630 are cheap and common to the 1980's motor controllers.

Pin 1		Backward
Pin 2		Ground
Pin 3		Unused
Pin 4		Forward
Pin 5		Motor 1
Pin 6		Unused
Pin 7		Power
Pin 8		Motor 2

You can run the Robbie Jr on 5V 800 milliamps. Yes, you can only power the h bridges if you only want to bot to move and nothing else...but what kind of challenge is that?

M6111B-24 is still quite a mystery to me.

8622EY is the audio chip.
Pin 1 is power
Pin 13 is ground
Pin 15 is the sound output.

Robie Jr circuit bending

In order to move beyond my plug and play Arduino component syndrome I've decided to try and hack a robot with out removing it's exiting behaviors / circuit board. I've been analyzing the simple circuit of the Robie Jr to see if it is possible to initiate behaviors manually. Here is the initial setup where I am trying to do some circuit bending to see if I can toggle the behaviors by shorting parts of the circuit. So far so good...