How you istall a new device to MSX-dos ?

[Kari LAMMASSA Juhani Lammassaari]

Hello there,

In MIDIIO4.com there was created a new device MID: , which could be 
treated as a new drive. (with commands bload, bsave, save and load etc.)
(MIDIIO4.COM connects two MSX:s equiped with Yamaha SFG-05 through midi 
cable.)

Question is :

How do you attach a new device (as CON ,AUX, PRN <drive> ) to msx 
operatimg system ?
Do you have to catch all the hooks concerning the device handling ?

If somebody knows, please let me know. 

Greetings, Kari