In his latest release, Piers introduces version 0.2.0 of the Software Defined ROM. This new update transforms a single device into a flexible multi-ROM emulator. With it, Piers breathes life into a VIC-20, a Commodore 64, and a 1541 disk drive—each missing critical ROM chips.
The Software Defined ROM replaces several ROMs with just one module. It’s ideal for enthusiasts restoring classic systems or creating custom mods. With this version, multiple ROM images can be served simultaneously using dynamic chip select lines and firmware logic.
Real Hardware, Real-Time Results
First, Piers demonstrates the upgrade on a 1541 disk drive. Two missing ROMs are replaced using a single module and a few jumper wires. The drive boots successfully, confirming the setup works.
Next, he restores a VIC-20 missing both kernal and BASIC ROMs. The system boots cleanly after routing chip select lines to the Software Defined ROM.
Finally, a Commodore 64 is brought back to life. It’s missing three ROMs—kernal, BASIC, and character. Despite this, the system runs smoothly with only one module installed.
New Features in Version 0.2.0
This update includes several powerful enhancements:
- Status LED shows when the ROM is ready—boot time is under 3 milliseconds.
- Logging support helps users track firmware behavior and chip performance.
- Dynamic pin mapping allows users to configure custom PCB layouts via JSON.
- Firmware inspection tool reads ROM data from compiled firmware binaries.
Additionally, a new hardware revision (version F) is in development. It adds support for easier pin access and cleaner wiring. This change reduces the need for soldering and improves installation for custom projects.
Preparing for Future Systems
Piers explains how this solution might support complex machines like the Commodore PET. Because the STM32 microcontroller has headroom at 84 MHz, it can easily emulate multiple ROMs. Even 2332 ROM support looks promising with minor software tweaks.
The entire demo runs from a single ROM module. Impressively, the C64 used for filming stays powered on and stable throughout the shoot.
Why This Video Matters
If you’re restoring vintage systems or building modern mods, this update is worth your time. Piers explains each step clearly while demonstrating real hardware results. He combines technical depth with accessible presentation, making it easy to follow along.
The Software Defined ROM simplifies what used to require multiple chips and complex wiring. Now, one module can serve everything—with performance to spare.
