The binary editor was a bit awkward to use. I simplified this and added the terminal's arrow keys to move around.

How to use: 

like shown in the photos, the STM32F407GT6 board is plugged into a STM to Z80 adapter board.

This board makes the connection to the serial port of the STM board and a connector is available to connect an FTDI basic or similar USB to serial converter. Open a terminal at 115200 bauds N81, and set ANSI terminal.

There was a compilation error that was simple to correct. In Core/Src, there's a file sysmem.c. Edit it and add this include:

#include <sys/types.h>