The JPL64 Emulator has reached a new milestone with version 0.03. Developed entirely from scratch by James Purcell (JPL), this Commodore 64 emulator continues to evolve with impressive attention to detail.
Unlike many C64 emulators that borrow from shared codebases, the JPL64 Emulator is written entirely from the developer’s own understanding of the system. No external code was used. It supports key features including the 1531 mouse, DigiMax, TAP files, most cartridge formats, 16MB REU, and D64 disk images via IEC emulation.
The standout improvements in version 0.03 revolve around SID audio emulation. Filters are now more accurate, ADSR envelopes are cycle-exact, and the implementation includes real-world quirks of the original chip. Waveform mixing has also shifted to look-up tables, offering cleaner and more faithful sound output. Ring modulation, another iconic SID feature, now behaves more reliably.
Additionally, this version upgrades the built-in debugger. Pressing F10 activates the debugger, and users can step through CPU cycles using the arrow keys. Though it’s still in early stages, the debugger is already proving useful for development and testing.
Display settings have also improved. Fullscreen mode (F11) is now supported after selecting a proper 50Hz display resolution, such as 1920×1080@50Hz. Joystick support is cleverly mapped to the numeric keypad, making gameplay accessible without external controllers.
Past updates laid critical foundations. Version 0.02 added EasyFlash HIROM support, VIC sprite collision detection, and more accurate CIA timer behavior. Version 0.01 marked the initial release, establishing a solid base for further development.
While the JPL64 Emulator isn’t aiming to dethrone established emulators like VICE or Hoxs64 just yet, it offers something unique: a personal, from-scratch take on C64 emulation that’s rapidly improving.
Users are encouraged to test the emulator and share feedback. Purcell remains open to criticism and suggestions, making this a truly community-driven effort.
For anyone interested in C64 emulation, particularly from a developer’s perspective, the JPL64 Emulator is absolutely worth exploring.
