Software Defined Retro ROM - ultimately flexible replacement ROM

A drop-in ROM replacement for vintage 8-bit computers that solves the fundamental limitations of existing solutions. Built around an STM32F4 microcontroller, SDRR delivers true flexibility, replacing 2364, 2332 and 2316 ROMS, through software configuration while fitting in the exact footprint of the ROM socket. This video introduces the project and demonstrates why existing ROM replacements fall short - from inflexible hardware configurations requiring physical modifications, to tedious programming workflows that interrupt development, to bulky adapters that may not fit properly in existing systems. SDRR addresses these problems with a software-defined approach: configure ROM types and chip select behavior through makefile configuration, reprogram in-system via 3-wire SWD without removing the chip, and achieve all this in a compact design that fits the original 2364/2332/2316 ROM footprint. Live demonstrations show SDRR working in C64 and VIC-20 systems, including real-time reprogramming and configuration changes. The complete solution costs under $5 per board in low volumes (much cheaper in high volumes) and is fully open source. Perfect for diagnostics, development, system restoration, and anyone working with PET, C64, VIC-20, IEC and IEE disk drives, and other 8-bit systems requiring 2364, 2332, or 2316 ROM replacements. Github Repo: https://piers.rocks/u/sdrr ⏰ **Timestamps** 00:00 🚀 Introduction 00:12 📋 Background 01:33 🔒 Today's ROMs - inflexible 02:46 ⏳ Today's ROMs - tedious programming 04:26 📦 Today's ROMs - bulky replacements 05:15 🎯 Solution - flexibility 05:47 ⚡ Solution - easy programming 06:16 📏 Solution - compact 06:26 💰 Solution - low cost 06:48 🔓 Solution - fully open source 07:00 🖥️ Demo - C64 kernal 07:50 🔧 Demo - C64 dead test ROM 08:26 🎨 Demo - C64 character ROM 09:34 🔄 Demo - reprogramming in-situ 12:09 ⚙️ Demo - ROM config 13:46 🛠️ Demo - building and flashing 14:55 🎮 Demo - Vic-20 dead test ROM 15:34 📂 Open source 15:47 💸 Build cost 16:28 🎬 Wrap up Video content copyright (c) 2025 piers.media Limited. All rights reserved.