Hi,

Your loop is not correct :

cout: jnb TI,cout
clr TI
mov SBUF,a
jmp cout

Here you're waiting for TI=1 to be able to send next character, but the first time, no character are send, the TI is never set...

Try this :

cout:
mov SBUF,a
jnb TI,$
clr TI
jmp cout