Update 1: This also works on the DSi and the DSi XL as long as your flashcard is supported!
Update 2: While the article isn’t technically out of date (It was originally written sometime in early 2008), the 3DS is about to be released with support for some sort of Virtual Console for Gameboy Games making this tutorial potentially out of date – 12/02/2011
To play GBC games such as Pokemon Gold and Silver on the DS, you have a few options. One of them is to use Goomba Color to create a Gameboy Advance rom package, and then play using a Slot 2 flash device. The other way (that I use!) is to use Lameboy DS.
I think Lameboy is the preferable option, because it does away with the need for a Slot 2 flash cart (If you haven’t already got one!), and secondly because it emulates the Real Time Clock needed to play Pokemon games properly.
To get started, you’ll need to have:
Start by downloading the latest version of Lameboy
Copy it over to the storage of your card, along with your GB/GBC roms. [Do NOT ask me where to find roms!] Launch Lameboy from the menu of your card, and hopefully you should be able to play some classic games!
If it crashes, or you get a solid colour screen, check you’ve used the correct DLDI file. If that doesn’t fix the problem, I’d redownload each file to ensure against corruption. Otherwise, you might ask for help on the Pocket Heaven, or GBA Temp Forums.
Permanently saving progress is a little different in Lameboy. In games such as Pokemon, you save like normal using the menu. This only saves into RAM, however. To save to your flash cart, press the X button and Lameboy will transfer the save into a .sav file! Otherwise, you’ll be scratching your head wondering why it didn’t save!
I’ve managed to play up to Goldenrod City in Pokemon Silver without any trouble. One thing to note though, is to not press X immediately after you Save in game. It’ll lock up, without saving (As I found out!)