Today in Guayaquil I had three interesting finds.
I bought some batteries for 15 cents each in packs of 2 — AA and AAA — brand SQMY, in the SONY font. They seem OK so far. The Kodak brand in the same shop cost $0.70; other batteries nearby cost $1 each.
The really interesting find was the cheap computing hardware.
I bought a video game machine, named "Brick Game", labeled entirely in English, for $2.40. Features:
It advertises "14000 [games] in 1" but most of the games are variants of Tetris. It also includes:
Some of the games blink a few pixels on and off at about 10Hz to indicate something "special" (the head of the snake, the snake food, special bomb blocks in Tetris, the frog in Frogger) but none so far use grayscale.
The sound is mostly square waves with no dynamic range, plus some white noise; there's a button that adjusts the volume.
Presumably the low price is due to integrating everything into a single chip, but it's still inspiring to find such a capable device on the market for $2.40. I have been more worried about the cost of non-processing parts (LCD, buttons) than CPU and I/O pins. Imagine if it also had Flash (it forgets high scores if you take out the battery), a reasonable amount of RAM (I think it has a few hundred bits: it needs 200 bits for the screen, 11 for the score, and 11 for the high score, plus a few more; but it doesn't seem to have had the budget for the 276-520 bits you'd need to have separate high scores per game.)
The back of the LCD is connected to the computer board with zebra strip; the computer board has 18 contacts on one side of the LCD and 19 on the other, which would be enough for 342 pixels if it worked that way. (It's harder to see and count the LCD contacts.)
The keyboard is on a separate (double-sided, silkscreened) PCB with a six-wire cable connecting it to the computer board.
With the six wires to the keyboard, the two wires to the battery (the negative one of which is connected to one of the keyboard wires, which is strange), and the two wires to the speaker, we have 46 pins in total, which would require a rather high-end microcontroller to control if you had to do it all in one chip.
The whole thing fits in my shirt pocket and weighs perhaps 100g.
The case feels pretty robust, although I haven't really put a lot of stress on it. I think its light weight would probably help a lot with robustness against accidental falls, and the shape probably provides a bit of robustness against crushing, but if any weight landed on the LCD, all bets would be off.
Imagine if you had a powerful microcontroller, a flash chip, a headphone/microphone jack, the ability to use the speaker as a microphone, and an LED for short-range communication. Now you could support:
If you had a USB interface, perhaps you could support transmission into the internet via HID, perhaps with a web-based interface. I'm not sure how to get data out of the computer, though. Save files onto a USB mass storage device? Audio communication via the headphone/microphone jack?
Many of the TVs I've seen here in Ecuador (not all, but many) have a yellow RCA jack for composite video input. That could provide a higher-bandwidth video output medium at times when a TV is handy and you want to use it while sitting down.
I suspect the whole device would be noticeably smaller if it wasn't trying to mimic the form factor of clamshell games like the GBA.
The third interesting find was a tiny Coby FM radio.
Play testing shows that this is enough computational power to keep kids (or me) entertained for hours. Perhaps this shouldn't surprise me, given its evident market success here in Ecuador — I've found it for sale in four different shops. The machine does seem to crash a lot, though, which limits its appeal somewhat.