Comparing Bare Silicon On Two Game Boy Audio Chips

June 27, 2020 by Al Williams 2 Comments

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.

The Nintendo Game Boy Color Is An Aircon Remote

April 29, 2020 by Jenny List 5 Comments

Those of you who are familiar with 1990s handheld consoles may recall that Nintendo’s Game Boy Color had an infra-red receiver and transmitter. The thought of a handheld computer with infra-red capabilities interested [jg], who immediately set about converting it into a remote control for an air conditioner.

The Game Boy doesn’t have dedicated infra-red remote control hardware, instead the IR diodes appear to be connected to I/O lines. Thus the bitstream bas to be bit-banged, and takes the processor’s entire attention when transmitting. The software is neatly placed on a reprogrammed bootleg cartridge.

It’s an interesting read in terms of the approach to reverse engineering, for example finding the parameters of 37 kHz infra-red remote control by trial and error rather than by a quick read up on the subject, or searching for information on National air conditioners and finding nothing, but not searching the National brand itself to find that a search on Panasonic air conditioners would likely give all the information needed. But the end result operates the appliance, so it’s good to record a success.

This isn’t the first time we’ve seen a Game Boy control something, though we can’t recall seeing another using the IR. Need a brilliant overview of the Game Boy? We’ve got you covered.

Thanks [Roel] for the tip.

Header image: Evan-Amos / Public domain.

Investigating The World’s Rarest Game Boy

February 27, 2018 by Tom Nardi 20 Comments

Early last year, a very unique Game Boy Color showed up on Chinese shopping site Taobao. Rather than the rather anemic-looking display of the original GBC, this version was modified with a modern IPS LCD. Even in the pictures shown on the product page, it was clear the display on this unit was far more advanced than anything Nintendo ever packed into a Game Boy. The retro gaming community went wild, and soon the site was overwhelmed with orders. The majority of the sales were canceled by the seller, and it’s believed as few as 75 of these hacked GBCs were actually shipped out.

Thanks to one of his viewers, [Colin] was able to get his hands on one of these extremely rare customized handhelds. Clearly a man after our own heart, his first inclination was to tear the thing apart and see how they built it. While he had a fairly good idea of how they managed this hybrid of modern and classic technology, there were a couple of surprises inside.

The device has a completely stock main board, and as such works and plays like a normal GBC. But upon flipping the main board over, [Colin] found a nest of thin magnet wire connecting the new display controller to individual buttons on the front panel. As he later confirmed when he reassembled the system, this allows the user to adjust the display’s brightness by holding “Select” and using the directional pad.

As for the screen itself, the big surprise was that it’s clearly pulled out of a relatively recent smartphone. The screen is physically much larger than the opening in the GBC’s front panel, but through some software trickery the image is displayed only in the area that’s visible to the player. [Colin] managed to get a hold of a few contacts “in the know” who confirmed to him that both the hardware and software for the display controller were specifically created for this application, and are unlikely to be duplicated by anyone else.

Considering most of the Game Boy hacks we cover are about somebody jamming modern hardware into them, it’s an interesting change of pace to see a group that was so adamant about retaining as much original hardware as possible while still managing to improve the user experience.

[Thanks to Doc Oct for the tip]

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Writing A New Game For The Game Boy Color

June 20, 2017 by John Baichtal 12 Comments

If you’re bored with the Game Boy Color’s offerings, it’s understandable: it’s been around for nearly 20 years, and doesn’t get a lot of new releases these days. [Antonio Niño Díaz] spent over a year coding a game for the GBC: µCity, a Sims City style game. He designed the graphics and even wrote his own music.

[Antonio] did all the programming in Assembly Language, creating modules for managing traffic and the power grid, building creation and destruction, as well as disaster simulations. He has extensive notes in his GitHub page detailing each module and describing how it all works together. He’s given it a GPLv3+ license, so hack away.

The ROM works on emulators, but [Antonio] has verified it works on the original hardware; it just reduces the number of saved cities to accommodate the handheld’s lesser stats.

Hackaday loves our GBC: we’ve written up DIY coprocessors for the GBC, adding an audio amp, and even making a solar-powered Game Boy.

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Tiniest Game Boy Hides In Your Pocket

November 28, 2016 by Mike Szczys 26 Comments

This is likely the world’s smallest fully-functional Game Boy Color, able to play all of the games using the tiny direction pad and buttons, with onboard display and battery and in the original form factor. This is an incredible hack which presents a tour de force in hardware and software. This will easily rank in the top five hacks you’ve seen this year.

I’m sure that many of you have fond memories of your first handheld games. This will be Game Boy for most, and we admit they had fairly decent portability and battery life that puts many smart phones to shame. Despite this, Sprite_TM always dreamed of an eminently more portable version and to his adolescent delight he discovered a key chain version of the Game Boy. Unfortunately, he was duped. The keychain looked like a Game Boy but only functioned as a clock.

But now, decades later, technology has progressed as have his own skills. For his talk at the 2016 Hackaday SuperConference, Sprite_TM actually built his childhood dream.

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DIY Coprocessors For The Game Boy Color

November 9, 2016 by Brian Benchoff 32 Comments

Back in the olden days, when video games still came on cartridges, the engineers and programmers making these carts had a lot of options. One of the most inventive, brilliant, and interesting cartridges to come out of the 90s was Star Fox for the Super Nintendo. Star Fox featured a coprocessor chip, the Super FX, that was effectively a GPU used to draw polygons in the frame buffer. Without this, Star Fox wouldn’t be 3D, Yoshi’s Island wouldn’t be as cute, and there wouldn’t be an always-on processor in your computer with the potential to spy on everything you do.

The Super FX chip, the Capcom-developed Cx4 coprocessor, and the Nintendo DSP all lived in a cartridge, but the technology to put a better computer in a cartridge never made it to Nintendo’s handheld devices. Cheap, powerful microcontrollers are everywhere now, and it’s not that hard to make a board with card edge connectors, leading [Anders] to build a Super FX for the Game Boy Color.

Game Boy cartridges are simple — just a memory controller and some memory is all you need. Drop in a microcontroller, and you have a Game Boy coprocessor. This cartridge features the MBC1 memory bank controller, 512kB of Flash, and 8KB SRAM. These are fairly standard parts, but there’s one last trick up the sleeve of this board: a KE04 from NXP, an ARM Cortex-M0+ microcontroller running at 48MHz . This microcontroller is, effectively, the GPU for the Game Boy.

This ARM-powered coprocessor is able to convert the framebuffer into tiles in just 2ms, giving the system plenty of time for image processing and rendering. Due to the limitations of the Game Boy, the best resolution offered by this coprocessor is either 160×96 or 128×128 pixels, short of the complete 160×144 pixel display in the Game Boy Color.

Even though [Anders] is still working on programming this thing to show off the power of his Game Boy coprocessor, he has a few demos to show off. The most impressive is a Wolfenstein-like clone. That’s extremely impressive and categorically impossible on a stock Game Boy Color.

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Use The Internet To Get Your Kadabra To Evolve

April 1, 2015 by Bryan Cockfield 13 Comments

If you grew up playing Pokemon Red or Blue, you might have moved far away from your childhood friends by now. If you’re still playing Pokemon Red or Blue, you can now literally reconnect with these friends using [Pepijn]’s new and improved Game Boy link that lets players trade Pokemon over the internet.

Based on [Pepijn]’s previous work building an Arduino-based Pokemon storage system (which was inspired by a separate project that was able to spoof trades), the device allows a Game Boy (including Pocket, Color, and Advance versions) to connect to the Internet via a Teensy shield. The online waiting room software is called TCPoke which facilitates the Internetting of the Game Boys. From there, all you have to do is connect via the project’s wiki!

The TCPoke software is available on the project’s site. Also, be sure to check out the video below which shows a demonstration of how the software works. There is noticeable delay compared to a direct link between Game Boys, but it functions very well. We didn’t see this link system work for a battle, but it would be interesting to see if it is possible. If so, you might never have to go to a Pokemon League meeting again!

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