What’s inside a Speak & Read cartridge? A enormous pile of goofy, that’s what.
The first thing you’ll notice is that whoever installed the chip in this board appears to have screwed up— only half the legs are inserted into holes. The second thing you’ll notice is that there are no holes for those legs. Half of the chip is just sort of dangling in the air.
The third thing you’ll notice, once you figure out what the chip actually is and find the datasheet, is that half the pins are Not Connected. This was actually an sensible design decision because wait what no wtf i can’t even.
It’s a serial chip that loads addresses in 4-bit nibbles. It takes in twenty bits for addressing 16K. Two bits are discarded. Four are used for the internal chip select. It wants -9V for VDD.
Much respect: this was designed in an era where chip layout was perpetrated on paper by the pocket protector brigade armed with rolls of black tape, sharp rocks, and hope. But still, ordinary EPROM had been around for a decade by 1980. This chip had to be incredibly cost-driven, and I’d love to hear the story of how it ended up this way.