#onerom — Public Fediverse posts

Piers Rocks Explains the One ROM Firmware Rewrite
#OneROM #RetroComputing #PiersRocks #Commodore64 #C64 #RP2350 #RetroHardware #Firmware
https://theoasisbbs.com/piers-rocks-explains-the-one-rom-firmware-rewrite/?fsp_sid=11970

It's mesh night at @foulab in #Montreal tonight. This is a casual in-person meetup of local mesh networking folks. If you're curious, drop by. https://foulab.org

I'm going to be bringing a ridiculous personal project that lets my 8-bit Tandy Color Computer 3 from 1986 talk on the #MeshCore network.

It's early-stage and the software is far from complete, but I can demo a whole CoCo -> #OneROM -> #Swift plugin -> UART -> Heltec V4 -> LoRa mesh stack now.

Come by after 19:00 and say hi!

One ROM CLI Guide Covers Programming, Slots, and Live ROM Editing
#OneROM #RetroComputing #ROMReplacement #CommandLine #Commodore64 #Amiga #VintageComputing #RP2350 #RetroHardware #OpenSourceHardware
https://theoasisbbs.com/one-rom-cli-guide-covers-programming-slots-and-live-rom-editing/?fsp_sid=10826

Now with the WS2812 LED via PIO (Programmable IO State Machine), and swift-mmio (because memory mapped I/O in #Swift is… weird).

```swift
while true {
morse.send(.s, in: .red)
morse.send(.w, in: .amber)
morse.send(.i, in: .green)
morse.send(.f, in: .cyan)
morse.send(.t, in: .violet)

// `send` already emitted a letter gap; top it up to a word gap.
delay(microseconds: Tick.wordGap - Tick.letterGap)
}
```

#OneROM

I recognize that the global audience for this exact kind of thing might be just me (I'd be truly surprised if THERE ARE DOZENS OF US!), but…

I’m pretty excited that I just managed to build a rudimentary proof-of-concept plugin for #OneROM (https://onerom.org) in Embedded #Swift ! (and it actually runs on the Fire 28 C)

One ROM Hardware Refresh Adds RGB LEDs Across the Range
#OneROM #PiersRocks #OpenSourceHardware #RetroComputing #RetroHardware #Commodore64 #Amiga
https://theoasisbbs.com/one-rom-hardware-refresh-adds-rgb-leds-across-the-range/?fsp_sid=9464

New version of #OneROM is available:
https://www.youtube.com/watch?v=ZT2kdvImPFU
#retrocomputing #osh

OneROM Updates Add New Amiga, Sinclair QL, Pinball, and ECU Tests
#OneROM #OneROMUpdates #PiersRocks #RetroComputing #Amiga #SinclairQL #EPROM #VintageComputing #RetroHardware #Pinball
https://theoasisbbs.com/onerom-updates-add-new-amiga-sinclair-ql-pinball-and-ecu-tests/?fsp_sid=7465

OneROM Amiga Review: Retro Hack Shack Tests a Programmable ROM Replacement
#OneROM #Amiga500 #RetroHackShack #CommodoreAmiga #KickstartROM #RetroComputing #VintageComputing #AmigaRepair
https://theoasisbbs.com/onerom-amiga-review-retro-hack-shack-tests-a-programmable-rom-replacement/?fsp_sid=7425

One ROM Switching Brings Software-Controlled Kernal Selection to the Commodore 64
#Commodore64 #VIC20 #OneROM #PiersRocks #RetroComputing #C64 #JiffyDOS #RBCP #8BitComputing
https://theoasisbbs.com/one-rom-switching-brings-software-controlled-kernal-selection-to-the-commodore-64/?fsp_sid=6754

One ROM Web: Browser Programming for Retro ROM Replacements
#OneROM #OneROMWeb #PiersRocks #Commodore64 #C64 #RetroComputing #EPROM #RP2350 #WebUSB #VintageComputing
https://theoasisbbs.com/one-rom-web-browser-programming-for-retro-rom-replacements/?fsp_sid=6410

One ROM Plugin Demos Show a C64 Rewriting Its Own ROM
#Commodore64 #OneROM #RetroComputing #PiersRocks #C64 #OpenSourceHardware #VintageComputing #RetroHardware
https://theoasisbbs.com/one-rom-plugin-demos-show-a-c64-rewriting-its-own-rom/?fsp_sid=5216

One ROM Plugins Bring Live USB Control to Retro Systems
#Commodore64 #OneROM #RetroComputing #RetroHardware #PierRocks #RaspberryPi #C64 #EmbeddedSystems #VintageComputing #RetroTech
https://theoasisbbs.com/one-rom-plugins-bring-live-usb-control-to-retro-systems/?fsp_sid=4680

One ROM 0.6.7 Adds Live USB Control and New CLI Tools
#OneROM #RetroComputing #Commodore64 #VintageComputing #ROMReplacement #PiersFinlayson #RetroHardware
https://theoasisbbs.com/one-rom-0-6-7-adds-live-usb-control-and-new-cli-tools/?fsp_sid=4512

One ROM Benefits: Piers Rocks Weighs 10 Reasons to Use It and 5 Reasons to Hold Back
#OneROM #PiersRocks #Commodore64 #Amiga #RetroComputing #OpenSourceHardware #EPROM #RetroHardware
https://theoasisbbs.com/one-rom-benefits-piers-rocks-weighs-10-reasons-to-use-it-and-5-reasons-to-hold-back/?fsp_sid=4100

One ROM Family Expands with New Open Source Retro ROM Options
#OneROM #RetroComputing #Commodore64 #Amiga #OpenSourceHardware #PiersRocks #RetroRepair #VintageComputing
https://theoasisbbs.com/one-rom-family-expands-with-new-open-source-retro-rom-options/?fsp_sid=3669

One ROM Hardware Guide: Getting Started with One ROM #1
#RetroComputing #OneROM #HardwareHacking #8bit #VintageComputing #ROM #Commodore #RetroTech #DIYElectronics
https://theoasisbbs.com/one-rom-hardware-guide-getting-started-with-one-rom-1/?fsp_sid=3030

One ROM 40: A 16-bit Kickstart Replacement With a Browser Logic Analyzer
#OneROM #Amiga #Kickstart #RetroComputing #RP2350 #PIO #DMA #LogicAnalyzer #WebAssembly #OpenSourceHardware #HardwareHacking
https://theoasisbbs.com/one-rom-40-a-16-bit-kickstart-replacement-with-a-browser-logic-analyzer/?fsp_sid=2751

OneROM RAM Mode Turns ROMs Into RAM
#OneROM #VIC20 #RetroComputing #Commodore #6502 #HardwareHacking #OpenSourceHardware #PIO #DMA #RP2350
https://theoasisbbs.com/onerom-ram-mode-turns-roms-into-ram/?fsp_sid=1534

Pico Flash Web Flasher Makes Pico Updates Easy
#RaspberryPiPico #RP2040 #RP2350 #WebUSB #PicoBoot #UF2 #Firmware #OpenSource #RetroComputing #OneROM
https://theoasisbbs.com/pico-flash-web-flasher-makes-pico-updates-easy/?fsp_sid=1317

Atari 2600 Cartridge Emulation – Part 4

In Part 3 I finished by noting that I’d sent off some OneROM boards to be made. This posts looks at what happened when I got them back.

OneROM is a replacement for 24-pin or 28-pin (EP)ROMs used in much vintage hardware, designed by ‘piers rocks’. There are two versions of each type, one based on an STM32 and one on an RP2350.

There is a lot of documentation available and a suite of tools that is growing in ease of use almost daily.

Key links:

• Main site: https://onerom.org/
• Getting started: https://onerom.org/start/
• Main documentation: https://github.com/piersfinlayson/one-rom
• YouTube channel with much of the development process: https://www.youtube.com/@piers_rocks

Manufacturing

To give you an idea of the speed of development, when I sent off the recommended design for the “Fire” (RP2350) 24-pin variant the recommended version was fire-24-c – i.e. revision C of the PCB. By the time I had the boards back, the recommended version was fire-24-d.

Massive credit to piers.rocks with the fabrication instructions. These boards have been designed for the cheapest, practical default options for manufacturing. The full process is described in full here: https://github.com/piersfinlayson/one-rom/tree/main/sdrr-pcb

Everything went pretty smoothly for me. I had to upload the Gerbers, BOM and positioning files from the “fab” area of the PCB revision in question. The one issue was that one of the capacitors wasn’t available, but there was an equivalent that had wide availability and the same properties as far as I could see, so I used that.

The cost was a little more than initially implied by the information I’d read but that is mostly because it doesn’t talk about postage, which naturally will be different for everyone. In the end the “all in” cost (postage and all) was around £8 per device for me.

First Install

Having received these back, there are a few options for getting them up and running:

• Download, install and use the Studio application.
• User the online Web installer.
• Build custom ROM firmware.

There are a number of default ROM configurations that can just be selected and run, but I’m going to try to get an Atari 2600 game ROM onto a OneROM emulating a 2732.

Unfortunately I hit a few issues straight away:

• The web application didn’t support the Fire (RP2350) version, only the Ice (STM32) version. Well, it didn’t when I started. After an issue or two and me asking in the discussion area, by the time I was having a second go – it did! More on that in a moment.
• The Studio application wouldn’t run on Windows for me. It does however run in my Linux Ubuntu VM fine. Studio does not allow me to create a custom ROM firmware however – I need to build it first.
• Building a custom ROM requires a fair bit of stuff to be installed, including rust, so that is parked for the moment.

What I did find, was that my boards started up in the RP2350 BOOT mode, so I got a drive appear ready to accept a UF2 file. But OneROM does not provide UF2 files.

It is apparently possible to install one of the firmware files (the onerom-fire-24-c*.bin files from the Releases area) using picoflash over USB, which I was able to do. But there is no default firmware for a 2732 and no means to get my Atari ROM built.

As I say though, asking on the discussion forums, by the time I got back to seeing if I had any reply, piers.rocks had updated the web tool to support building a custom ROM, which I subsequently went on to do.

Unfortunately I seem to have an issue now with my 4K ROM appearing as a repeating 2K ROM with only the first half present. After a bit of too-ing and fro-ing on the forums, it turns out this was a bug in the 2732 support. Once again, it was diagnosed and fixed withing 24 hours of having the conversation. There is a detailed analysis of the issue and solution in the bug report here: https://github.com/piersfinlayson/one-rom/issues/103

Build from Scratch

As part of attempting to get a firmware image containing my ROM, I went through the installation instructions to get a dev environment up and running. I was able to make some notes and sent them off, and again they were all included into some updated documentation within 24 hours.

The main information required is here: https://github.com/piersfinlayson/one-rom/blob/main/INSTALL.md

And it now includes full instructions on how to get everything built too.

For my ROM, I copied the ROM file into my build area and then had to create a configuration file for the build:

one-rom/config/a2600.mk

ROM_CONFIGS = \
file=spaceinv.bin,type=2732

Then use the make command detailing my board, revision, configuration to use and location of the toolchain:

~/src/one-rom$ MCU=rp2350 HW_REV=fire-24-c CONFIG=config/a2600.mk TOOLCHAIN=/usr/bin/ make

This leaves me with a firmware file in sdrr/build that I can now use with the Studio tool to load onto the OneROM.

At this point I can check it in an EPROM programmer if required (as per instructions in this video though, there are some caveats – do not use “Detect pins” or “Check ID” or equivalent operations – these often involve using higher voltages on the pins of real devices which will damage OneROM) and I can see the whole ROM is now intact.

At this point I can now put it into the custom cart as described in Part 3 – noting the small white arrow indicating pin 1 (opposite end to the USB socket).

And lo and behold – it works 🙂

My version of Fire has two “bank select” jumpers so I think it would be possible to allow selection between at least two different ROMs. Another option is to use the 28-pin version in place of the 27C512 used in the multi-cart described in Part 3.

Getting this going has been a really positive experience:

• The instructions for manufacturing are excellent, allowing me to get my first ordered PCB assembly done.
• The tools provided are first class and even though still under development are already very user friendly once you get to know what needs to be done.
• The documentation is comprehensive, and again still be optimised.
• The development videos are really useful and a great insight into what is required for something of this complexity.

Now I just have to work out what it is about Studio that my Windows installation doesn’t like, but as the web tool is constantly developed, the need for Studio is decreasing anyway and when I need the more complete tool, I’m probably already in my Linux VM anyway.

A massive thank you to piers.rocks for creating this, documenting it so well, releasing it as open source, and responding so quickly and positively to my questions. If this fits a use you have, I can recommend giving it a go.

Kevin

#atari2600 #OneROM #rp2350

OneROM Fire 40 Brings 16-Bit ROM Flexibility to the Amiga
#OneROM #Amiga #Kickstart #RetroComputing #Commodore #C64 #PCBDesign #RP2350 #RaspberryPi #HardwareHacking
https://theoasisbbs.com/onerom-fire-40-brings-16-bit-rom-flexibility-to-the-amiga/?fsp_sid=661

OneROM Versatile Emulator Review: Root42 Tests Fire and Ice in a C64 and 1541
#Commodore64 #C64 #Commodore1541 #RetroComputing #VintageComputing #HardwareRepair #OneROM #Root42 #8Bit
https://theoasisbbs.com/onerom-versatile-emulator-review-root42-tests-fire-and-ice-in-a-c64-and-1541/?fsp_sid=383

One ROM Fire 28: A Smarter Way to Swap Retro ROMs in 2026
#OneROM #RetroComputing #Commodore64 #HardwareHacking #ROMReplacement #ElectronicsRepair #OpenSourceHardware #RP2350 #STM32 #VintageComputers
https://theoasisbbs.com/one-rom-fire-28-a-smarter-way-to-swap-retro-roms-in-2026/?fsp_sid=305

Little sneak peek for the next video, which is already up for Patrons. It shows what you can do with #onerom.
#retrocomputing

USB Programmable One ROM Makes 28-Pin ROM Swaps Simple
#OneROM #RetroComputing #Commodore64 #C64 #DiskDrive1541 #Electronics #HardwareHacking #OpenSourceHardware #RP2350 #EPROM
https://theoasisbbs.com/usb-programmable-one-rom-makes-28-pin-rom-swaps-simple/?feed_id=7286&_unique_id=69528e73c6547