I found this instructables converstion on the "black goo," which is probably epoxy:
"Its there to reduce manufacturing costs. The IS no chip there, just a naked die. Its called "flip-chip" technology. The chip is bonded on tiny solder balls on the PCB, then gloop is applied. AIUI, concentrated formic acid will attack the package, but you won't be able to identify the underlying chip."
Thats ok. I may have come across sounding like I want to use this toy's circuit exactly -- I don't though. I just want to make my own circuit that performs a similar function, and I probably want to make quite a few copies. I want to be able to put my own sounds on there, so I need to be able to program it.
I have access to a board router at school. Mask-programming sounds out of reach, but a fuse-programmed device might work.
What kind of chip should I look for? Anyone know of a keyword that would help in my search? Also if anyone knows what those spring-switches are called...that would be awesome.
links for people referencing in the future:http://www.instructables.com/answers/Reverse-Engineering-how-do-you-get-to-the-chip-be/http://www.tech-faq.com/prom.htmlhttp://www.codepedia.com/1/Mask-programmed+ROM