Uploaded September 2009 | Updated September 2026, 2 hours ago
Costis is screwing around with the clock on a GBC and I just couldn't keep myself from trying it out. He quoted some pretty insane max clock speed and I wanted to see whether it would really go that high. Turns out it goes pretty high: ~24Mhz (~3x) for GBC games, and ~48Mhz (~6x) (!) for GB games. Normal speed is 8.338Mhz input, though GB games internally run at half speed (~4Mhz), which is why they can run much faster.
This is just a GBC hooked up to a frequency generator implemented on a Spartan-3E starter kit. No extra mods were done to the GBC. I plugged in my desktop speakers to the audio jack so you can hear it better.
The BIOS ROM can actually run at over 70Mhz but the screen glitches up pretty weirdly and my setup is too crappy to make it stable. At those speeds the drive strength on the FPGA and other details start to become much more important.
Costis' work:
http://www.its.caltech.edu/~costis/sgb_hack/
Improved frequency generator for S3EBOARD:
marcansoft.com/transf/freqgen.tar.bz2
Costis is screwing around with the clock on a GBC and I just couldn't keep myself from trying it out. He quoted some pretty insane max clock speed and I wanted to see whether it would really go that high. Turns out it goes pretty high: ~24Mhz (~3x) for GBC games, and ~48Mhz (~6x) (!) for GB games. Normal speed is 8.338Mhz input, though GB games internally run at half speed (~4Mhz), which is why they can run much faster.
This is just a GBC hooked up to a frequency generator implemented on a Spartan-3E starter kit. No extra mods were done to the GBC. I plugged in my desktop speakers to the audio jack so you can hear it better.
The BIOS ROM can actually run at over 70Mhz but the screen glitches up pretty weirdly and my setup is too crappy to make it stable. At those speeds the drive strength on the FPGA and other details start to become much more important.
Costis' work:
http://www.its.caltech.edu/~costis/sgb_hack/
Improved frequency generator for S3EBOARD:
marcansoft.com/transf/freqgen.tar.bz2
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Lots of yaks on the way to the mmiotrace hypervisor
Website: https://asahilinux.org
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In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
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I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
![Work stream: Writing a hypervisor Pt.12.5 [2021-05-25]](https://i.ytimg.com/vi/rdhD1tinF8c/mqdefault.jpg "Work stream: Writing a hypervisor Pt.12.5 [2021-05-25]
Mmiotrace hypervisor, maybe?
Website: https://asahilinux.org
Patreon: https://patreon.com/marcan
GitHub Sponsors: https://github.com/sponsors/marcan
In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
There is currently no set schedule for these streams, so subscribe and click the bell if you want to be notified when they happen.
I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
![Work stream: Linux bring-up from scratch [2021-01-19]](https://i.ytimg.com/vi/s58olssYwRc/mqdefault.jpg "Work stream: Linux bring-up from scratch [2021-01-19]
Porting and booting Linux from Torvalds tree
Website: https://asahilinux.org
Patreon: https://patreon.com/marcan
GitHub Sponsors: https://github.com/sponsors/marcan
In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
There is currently no set schedule for these streams, so subscribe and click the bell if you want to be notified when they happen.
I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
![Work stream: Writing a hypervisor [2021-04-29]](https://i.ytimg.com/vi/sKEj8z4H7PM/mqdefault.jpg "Work stream: Writing a hypervisor [2021-04-29]
Mmiotrace hypervisor, maybe?
Website: https://asahilinux.org
Patreon: https://patreon.com/marcan
GitHub Sponsors: https://github.com/sponsors/marcan
In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
There is currently no set schedule for these streams, so subscribe and click the bell if you want to be notified when they happen.
I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
