INT 14h,  19h    Write block (transfer from user buffer to FOSSIL)

      Entry:  CX         Maximum number of characters to transfer

              DX         Port number

              ES         Segment of user buffer

              DI         Offset into ES of user buffer

      Exit:   AX         Number of characters actually transferred

    A  "no-wait"  block  move of 0  to FFFFh  characters  from  the  calling
    program's  buffer into  the  FOSSIL outbound ring buffer. ES:DI are left
    unchanged by the call;  the count of bytes actually transferred  will be
    returned in AX.