spacewrench wrote on Sunday, February 10, 2008:
Yes, it’s an ARM7TDMI. There’s a ton of info about it, and I’m pretty sure I once saw the actual manufacturer / part number, but I can’t find it now. It looks like there was once a very active homebrew community, but it seems to have moved on to the DS, or to have gotten old / married / busy and gone away. <a href=“http://nocash.emubase.de/gbatek.htm”>Here’s</a> the best collection of info I’ve found in one web page.
There’s a <a href="http://sourceforge.net/projects/vba/>good emulator, VisualBoyAdvance</a>, and you can still get programmable cartridges for real hardware. I’m planning to use FreeRTOS on an old GameBoy to control a floor radiant heat system – I need to monitor several OneWire thermometers and control a relay to switch on pumps & so forth.
I couldn’t figure out how to upload stuff to the Files area, so I put my patches <a href=“http://www.mersenne.com/downloads/FreeRTOS-GBA.tar.gz”>here</a>. Includes a compiled copy of the demo program (“demo.gba”) so you can try it on the emulator without setting up a toolchain. Note that the compilation process requires a final preparation step (“gbafix”) where some magic numbers are poked into the binary header. You can get a copy of gbafix <a href=“http://darkfader.net/gba/files/gbafix.zip”>here</a>.