RetroChallenge 2018/04: C64 ROM Kustomizer

Recently I purchased the awesome C64 Reloaded MK2 from Individual Computers. There are many things to love about it:  a modern power supply, dual SID sockets with configurable output, clean S-video, auto-detection of SID/VIC chips (with the correct voltage!), and the list goes on. One of my favorite features is the ability to upload multiple kernal and character ROMs and switch between them. No more EPROM programming!

I learned how to customize the startup colors and text in the kernal ROM thanks to this brilliant post at Breadbox64. After going through that process several times, I decided that I was too lazy to manually do it again.

So I cracked open a beer, knocked off some programming rust and whipped up a JavaScript prototype that works fully in the browser. It’s ugly and held together with duct tape and paper clips, but it proved out the idea. The C64 ROM Kustomizer was born!

The functional-but-ugly prototype

For my RetroChallenge, I want to take this project further and achieve the following:

  • Clean up the code a lot
  • Make it pretty – the fine folks at have graciously given me permission to use their fantastic C64 TrueType font in the “kernal preview” window!
  • Test editing some other ROMs (already tested with a factory ROM and JiffyDOS)
  • Get it hosted on my site so people can use it

I will post updates about my progress at least weekly. Wish me luck!

Author: John Cook

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