Hand-Held Legend Articles | Game Boy Modding – Hand Held Legend, LLC


Is the Game Boy a Computer? Colin (This Does Not Compute) - June 06 2016, 0 Comments

This is the first post in an occasional series by Colin from This Does Not Compute.

One of the things that has always interested me are devices that should be computers, but aren't really. We generally think of "computers" as multi-purpose systems, things that run an operating system and applications. But there are tons of devices out there that have processors and RAM but don't really run an operating system in the traditional sense. What is one very famous example of this that we are all familiar with? The Nintendo Game Boy series, specifically the original Game Boy, Game Boy Pocket, and Game Boy Color, sometimes referred to as the "DMG", "MGB" and "GBC" respectively.

I recently ran across the RealBoy emulator project (https://realboyemulator.wordpress.com). There are plenty of Game Boy emulators out there and this one isn't really any different... except for this excellent blog series that explains in depth how the original DMG works. It's meant as a primer in order to understand how the emulator's code works, but it's also an amazing look at the underlying hardware.

In short, the architecture of the Game Boy is pretty simple -- processor, RAM, and ROM. The first two reside in the console itself while the ROM (and some more RAM) is in the game cartridge. There's only a small amount of permanent code in the Game Boy hardware, basically just enough to get the device to perform an initial cartridge check. (The check is, in a way, a form of DRM; it makes sure that the game was licensed by Nintendo and not independently released).

The CPU is perhaps the most interesting part of the system. In the DMG, it's a Sharp LR35902. By all appearances it's a custom part, and in many ways it is, but designing an entire processor from the ground up just for a hand-held game system (or any game system at all really) isn't cost effective. So the Game Boy's CPU is actually based on the Zilog Z80, which was at that time -- and still is -- a common 8-bit processor. The Z80 itself was actually a binary-compatible version of the Intel 8080; not necessarily a clone, but capable of executing all the same instructions. There were some additions to the Z80 beyond that of the 8080, but the custom Sharp CPU wasn't just a rebadged Z80. It actually leveraged parts from both processor architectures, while omitting anything that wasn't relevant to a game console.

What to me at least, makes the Game Boy more of a device than a computer is that there was no traditional operating system layer, firmware, or anything standing in the way between the game and the hardware. After that initial check, the CPU simply ran any instructions presented to it by the game. Modern games are written using a high-level programming language like C, but older games were written in machine language telling the CPU exactly what to do and when. In some ways, the game itself was an operating system. (This is also partially why emulators aren't perfect -- you have to write high-level code that mimics how hardware works, whereas modern games, already written in a high-level language, can simply be ported to another platform)

You might be most surprised by the lineage of the Intel 8080. It was originally designed in 1974 (along with the Z80), and made its way into early PCs and even some arcade games like Space Invaders. But the 8080 also was the basis for subsequent Intel processors, like the 8086. The 8086 is where we get the common computer term "x86", as it spawned the 286, 386 and 486 CPUs. Those of course led to the Pentium series, and on to the modern processors we use in our computers today. It's crazy to think that in 1989 when it was released, the Game Boy actually shared some similarities with computers running Windows. It is in its own right, a computer... that also isn't.

This Does Not Compute is a YouTube channel (https://www.youtube.com/c/thisdoesnotcompute) about gaming, content creation and all things technology. Colin can be reached on Twitter @thisdoesnotcomp (https://www.twitter.com/thisdoesnotcomp) and Instagram (https://www.instagram.com/thisdoesnotcomp).

Update - Backlights - Game Gear - Buttons and Screens Kyle Capel - July 13 2015, 2 Comments

Here are a few updates for those of you who have been asking about when we will be restocked with various items. We will be away July 18th - 25th. Store will be open but orders won't go out until the 27th.

  • New Backlights Version 2.0: Completion date is set on the 24th of July. I hope to have them and available on August 1st. Sorry for the wati! Pushed back again...
  • Screens: Complete date was the 29th of June and is not the 27th of July...  hope to have them and available on August 1st. Sorry for the wati!
  • Buttons have been revised so the ETA here is August...
  • Game Gear/Lynx Backlights are back in stock
  • OSAKA LOCA order placed - and shipment is being prepared. Hope to start selling July 27th.
  • Clear GBC shells are on backorder. We hope to have a lot of them in by... (you guessed it) August... I HOPE

What other products would you like to see in the shop? Comment below.


New Backlight Sneak Peak Kyle Capel - July 07 2015, 3 Comments

Here are some photos of the new thinner backlight with a flat fcp cable. They look amazing! Colors even better in person, the pictures do not do it justice. Clocking in at 1.23mm, this is our thinnest backlight ever. No cutting required!!


**NEWS*** New Thinner Backlights with Flat FCP Coming Soon Kyle Capel - June 18 2015, 5 Comments

Thats right, we are designing a thinner, flatter, easier to install DMG/MGB backlight. The new model will not sacrifice the HHL quality that you have come to recognize and appreciate. You can expect a flat FCP cable with solder pads for and installation without cutting the plastic DMG frame. The cable will be to the left, like other models, for worry free MGB installation. Knowing the timeline for this process, samples are set to arrive in June. After approval production will begin and we can expect to have them in a few weeks into July. Lets hope for an on-time delivery. Would you like to see a pre-order for these units?

In the mean time, check out our new GBC Frontlights. Now on SALE! And DMG buttons are coming, screens for the DMG, MGB and GBC too.

Introducing the Game Boy Builder Kyle Capel - April 22 2015, 0 Comments

Here at Hand Held Legend we are excited to offer tools to our community members to better enhance their experience on our website. The Custom Game Boy Builder will do just that as it will be at your disposal to customize many aspects of your vintage DMG before you purchase custom parts. Modification categories include color choices for the shell, buttons, screen, backlight, and LEDs. Spend some time creating and customizing the look of your DMG before you dish out your hard earned green. We hope to be able to offer this same builder for the Game Boy Color in the future. Let us know your thoughts and comments on the discussion page or in the comments below.

Click here to go to the builder

New DMG and GBC Colored Screens in Stock Kyle Capel - December 17 2014, 0 Comments

Find new custom colored screens for the original DMG and GBC with their original art work. We have altered some of the accent colors to stand out better against their new background. These are self adhesive and are 1.0mm thick for a flat fit on your DMG or GBC. Check these out on the products page. Your feedback is welcomed.
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