Int 14 Fn 164F  - Digiboard - Ccb Command - Buffer Set All                 [S]

   AX = 164Fh
   BL = size
   DX = port number (00h-03h) (04h-43h for XAPCM232.SYS)

Return: AH = status
       00h successful
       80h error
       FFh error

See Also: AH=16h"Digiboard",AX=164Dh