Custom Firmware for the MZ-RH1 – Ready for Testing (sir68k.re)

I’m so glad Minidisc is having a resurgence. I don’t know if I’ll end up getting a MZ-RH1, but for the lucky folks who do, nice to see they’ll get some nice QoL upgrades!

Looking through the code is really interesting! I've always wondered how the code for these sorts of embedded devices worked (namely microwaves).

I have an MZ-RH10 lying around somewhere that would be neat to try working on.

Some folks have recently done screen replacements on those and that might be worth doing first.

always wanted one of these models then prices skyrocketed. now there’s not much of a point as the primary novel feature, uploading, was reverse engineered for all other NetMD models (ones that take standard batteries and have screens that don’t burn-in), just need a WebUSB browser and go here: https://web.minidisc.wiki/

I'm on the MD Discord and been following all of this, a bunch of us updated before the official launch and found a few bugs in the process, but the firmware itself is fabulous.

> discovered a boot ROM mode that can be enabled by bridging two GPIO lines on the mainboard (HSALF / TP8232 / R853 and WDT / SL901) to ground

How do you even find something like this?

Really nice project – respect :) Finding that boot ROM mode by bridging GPIO lines is a great catch. Having a hardwired 'safety net' makes custom firmware projects much more viable. When you were testing the flasher, did you find the CXD2687's flash interface to be deterministic in its failure modes, or did you run into any race conditions/timing issues during the erase/write cycles?

Why is MiniDisc having a come back nowadys?

Your replacement MZ-RH1 OLED display modules are equally as impressive a project.

Love to see it :)