Heads up on our (DECromancer's) latest units...

[Joan Touzet]

Hey there, we had a complaint from a customer regarding a boot loop situation on an MFM Emulator bought from us (DECromancer) and wanted to share what we learned from the debug process with the list.

We've written a blog post about it (https://decromancer.ooo/posts/calibrate-mfm-voltage/) but, long story short, our newest units (S/N 070 and up) need the powerfail script's scaling factor adjusted to 0.1232 before enabling the systemd unit for auto-startup. Thankfully, this is a one-line change to /etc/mfm_emu.conf.

I've even seen some individual variation from unit-to-unit, so I'd personally recommend anyone using the emulator in a variety of old machines (which may have sagging 12V lines) to go through the simple calibration process described in the post to tune the scaling factor for their individual units.

Cheers,

Joan @ DECromancer