org &8000
ld a,2 ; mode 2
call &bc0e
call across ; top row
ld b,23 ; sides
.downloop
call star
ld a,80
call &bb6f
call star
djnz downloop
.across ; bottom row
ld b,79
.aloop
call star
djnz aloop
.star ; prints *
ld a,"*"
jp &bb5a