One Rom - One ROM To Rule Them All

The most flexible ROM replacement for your retro computer. It is highly configurable and low-cost. Get them fabbed at JLC for under $5 each in a quantity of 10 or more.

Based on a Raspberry Pi RP2350 (One ROM Fire 🔥) or STM32F4 (One ROM Ice ❄️).

One ROM is available as 24 pin and 28 pin versions, emulating nearly all systems' 24 and 28 pin ROMs, including any possible chip select configurations, and can serve different images to multiple ROM sockets simultaneously.

Replaces failed ROMs in Tandy, Commodore 64s, VIC-20s, PETs, Ataris, BBC, TIs, disk drives and many other types of systems.

ROM types replaced:

• 24 pin: 2704, 2708, 2716, 2732, 2316, 2332, 2364
• 28 pin: 2764, 27128, 27256, 27512, 23128, 23256, 23512

One ROM was formerly known as Software Defined Retro ROM (SDRR).

💰 Based on sub-$2 microcontrollers. Choose from Raspberry Pi (Fire) or STM (Ice)

⚡ Fast enough for Tandy, PETs, VIC-20s, C64s, 1541s, IEEE drives, etc. Support faster systems with higher end microcontroller.

📐 Same footprint as original ROMs - doesn't overhang the socket like other solutions.

🔌 USB version - no programmer required, program from your browser.

🚀 Quick Programming- build and flash in <10 seconds.

🛠️ Reflash in situ- no need to remove the ROM from the host when reprogramming.

⚙️ Software configurable chip select lines - no hardware jumpers required.

💾 Stores up to 16 rom images of different sizes and chip select configurations. Image selectable via jumpers.

📦 Replace multiple roms with one a single One ROM can replace up to 3 original ROMs e.g. all of C64 kernel, BASIC, character set.

🔀 Dynamic Bank Switching - switch between ROM images on the fly, e.g. different char ROMs.

💻 Hackable at runtime - change the ROM images being served and access telemetry from the ROM at runtime using AirFrog or other SWD probes.

🧩 Images combined automatically - no need to manually build up your own larger PROM image containing multiple retro ROMs.

🏭 Two layer PBC -  component on single-side, limited BOM for low manufacturing cost/complexity

🔓 Open Source software and hardware.

(These are sourced from our 3rd Party PCB supplier. The original project is available on GitHub with the user piersfinlayson and being produced under his LICENSE and permission)