Comparing Bare Silicon On Two Game Boy Audio Chips

We always look forward to a new blog post by [Ken Shirriff] and this latest one didn’t cure us of that. His topic this time? Comparing two Game Boy audio chips. People have noticed before that the Game Boy Color sounds very different than a classic Game Boy, and he wanted to find out why. If you know his work, you won’t be surprised to find out the comparison included stripping the die out of the IC packaging.

[Ken’s] explanation of how transistors, resistors, and capacitors appear on the die are helpfully illustrated with photomicrographs. He points out how resistors are notoriously hard to build accurately on a production IC. Many differences can affect the absolute value, so designs try not to count on exact values or, if they do, resort to things like laser trimming or other tricks.

Capacitors, however, are different. The exact value of a capacitor may be hard to guess beforehand, but the ratio of two or more capacitor values on the same chip will be very precise. This is because the dielectric — the oxide layer of the chip — will be very uniform and the photographic process controls the planar area of the capacitor plates with great precision.

We’ve decapsulated chips before, and we have to say that if you are just starting to look at chips at the die level, these big chips with bipolar transistors are much easier to deal with than the fine and dense geometries you’d find even in something like a CPU from the 1980s.

We always enjoy checking in with [Ken]. Sometime’s he’s taking apart nuclear missiles. Sometimes he is repairing an old computer. But it is always interesting.

Solar-powered GameBoy Color Never Runs Out Of Juice

solar_gbc

Instructables user [Andrew] was given a free, but damaged GameBoy color by a friend. The friend’s dog had done quite a number on the outside of the handheld, but it was definitely usable. ¬†After replacing some of the outer shell, [Andrew] decided that he would try tweaking the GameBoy to utilize a solar cell in order to keep the batteries topped off.

He bought a solar garden light for $5 and disassembled it, being careful not to damage the heavily-glued solar panel in the process. The GameBoy was pulled apart next, and the solar panel was soldered to the handheld’s battery leads. Once the wires were properly routed through the case, he reassembled the handheld and picked up a pair of rechargeable AA batteries to test things out.

[Andrew] tells us that the solar panel works nicely, and that simply setting it out face-down keeps his batteries charged and ready to go.

Stick around for a quick video demo of his solar-powered GameBoy.

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