Dump of ideas on how to hack the PO-33 ( The Pocket Operator by Teenage Engineering )
Trying to figure out the file format used on the audio backup. Maybe some modem audio thingy.
The PO uses the EFM32, but it has the debug connection locked. BUT FOR OUR LUCK SOMEONE WAS ABLE TO BYPASS IT https://limitedresults.com/2021/06/enter-the-efm32-gecko/ With EM Fault Injection tho, looks complex, but I'll try it out.