I have a collection of macros and subroutines that I very often use in my AVR assembler projects
The RLV12 Emulator uses a Atmega1284P MCU. Here you can find the full source code of the latest version that has been tested as well on the PDP-11/Hack and Plessey PDP-11 system as well as the binary
This is the updated RLV12 Emulator with a break-out board for all interfaces.
This is a small side project not only related to PDP-11, the basic idea was to first read and write to floppy drives with just a microcontorller and without a FDC (floppy disk controller) chip