You need to enlarge **tape** because your initialization zeroes 101 bytes.  

    section .bss
    tape resb 101

The teletype function uses the BL and BH registers as arguments.

    mov bx,0007h ;Display page 0 and Color 7 (if in graphics mode)
    mov ah, 0Eh
    mov al, byte [tape +di]
    int 10h