Int 49 Fn 10  - Ti Professional Pc - Crt - Write Block Of Characters With  [V]

   AH = 10h
   AL = attribute (becomes new current attribute)
   DX:BX -> string of characters to write
   CX = length of string

Return: nothing

Note:  AH=00h,04h,05h,0Bh,0Ch,0Dh,0Fh are documented as NOPs
BUG:   CX must not be 0000h on entry, or the system will crash

See Also: AH=01h,AH=02h,AH=09h,AH=0Eh,AH=11h