Boot into MSXPi-DOS
MSXPi comes with a 32KB EPROM containing MSX-DOS 1.03. This MSX-DOS has the required drivers to allow MSX to connect and use Pi as a disk drive. This new modified version was called MSXPi-DOS 1.04.
To boot into MSXPi-DOS, a disk image is required under Pi SD Card, on path /home/pi/msxpi/disks.
The boot disk is on image msxpiboot.dsk. Drive B: is on image msxpitools.dsk. After boot, it is possible to change disk images using command psetdisk.
All commands listed under http://retro-cpu.run/wiki/index.php?title=MSXPI:Specs:PT:DOS2) can be used.