I had the 50-in-1 kit that preceded it; my dad got it for me in either 1969 or 1970. Each of those X-in-1 kits had one or two "feature" components that were placed in the center. The feature components in the 50-in-1 kit were a solar cell and a PNP transistor. There was a selection of about 10 resistors and capacitors of various values; an inductor, a relay, a pot, a variable capacitor, a diode, an incandescent lamp, a buzzer, a galvanometer, and battery holders for AA and 9-volt batteries. The 50-in-1 kit didn't have a speaker; it came with a cheap high-impedance earphone with stripped/tinned ends on the leads. There were a couple of terminal screws on the board where you were supposed to attach these. It came with cut wires of various length, color coded, for making connections. It also came with a 50-foot length of some ridiculously small gauge wire which was intended to be used as a radio antenna. There were no integrated circuits; that came in later models.BF wrote:A 100 in 1 electronics project lab (or something to that effect). It had a bunch of small coiled "springs" you would pinch lengths of wire in to create connections between the components they were connected to in order to build circuits. Kind of like a modularized circuit board I guess.
Each of the components on the board was wired to the connection springs that BF mentions. They stuck up vertically out of the board, and you made a connection by bending the spring sideways and inserting a wire end in between the coils. Each of the springs was numbered. The manual contained a number of projects with instructions that told you which numbers to connect to each other, connect-the-dots style.
Some of the projects were cool, like the passive AM radio. Some were cheesy, like the "burglar alarm" that tripped the relay and sounded the buzzer when a strip of aluminum foil was broken. I remember being frustrated with some of the projects because I couldn't get them to work even after going over all of the connections carefully. My dad even went over some of them and couldn't find anything wrong with them either. Many years later, I realized the problem: the PNP transistor was absolute c**p. Based on the results I remember getting with with some of the simpler projects that included it (such as the light meter), it probably had a beta of about 2.