how to change characters font?

[ww33ww]

hello,

i find this code but i don't know how it works
please is there anyone know how to change characters font i need a sample example

push ds       ;
 pop es        ; make sure ES = DS
 mov bp,offset OurFont ;
 mov cx,02     ; we'll change just 2 of them
 mov dx,65     ;   A and B --> our A and B
 mov bh,14     ; 14 bytes per char
 xor bl,bl     ; RAM block
 mov ax,1100h  ; change font to our font
 int 10h       ; video interrupt
 mov ax,4C00h  ; exit to DOS
 int 21h   ;

     OurFont db 00000000b
                db 01111111b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01111111b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01100011b
             db 00000000b
             db 00000000b

             db 00000000b
             db 01111110b
             db 01100110b
             db 01100110b
             db 01100110b
             db 01111111b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01100011b
             db 01111111b
             db 00000000b
             db 00000000b