The following chart gives a brief description of the Exec functions that
control device I/O.  See the Amiga ROM Kernel Reference Manual: Includes
and Autodocs for details about each call.


                  Table 19-4: Exec Device I/O Functions
  ______________________________________________________________________
 |                                                                      |
 |     Exec Device                                                      |
 |     I/O Function                  Description                        |
 |======================================================================|
 |  CreateIORequest()  Create an IORequest structure (V36).             |
 |  DeleteIORequest()  Delete an IORequest created by CreateIORequest() |
 |                     (V36).                                           |
 |       OpenDevice()  Gain access to an Exec device.                   |
 |      CloseDevice()  Close Exec device opened with OpenDevice().      |
 |             DoIO()  Perform a device I/O command and wait for        |
 |                     completion.                                      |
 |           SendIO()  Initiate an I/O command.  Do not wait for it to  |
 |                     complete.                                        |
 |          CheckIO()  Get the status of an IORequest.                  |
 |           WaitIO()  Wait for completion of an I/O request.           |
 |          AbortIO()  Attempt to abort an I/O request that is in       |
 |                     progress.                                        |
 |______________________________________________________________________|


             Table 19-5: Exec Support Functions in amiga.lib
  ______________________________________________________________________
 |                                                                      |
 |        Function                   Description                        |
 |======================================================================|
 |          BeginIO()  Initiate an asynchronous device I/O request.     |
 |      CreateExtIO()  Create an IORequest data structure.              |
 |      DeleteExtIO()  Free an IORequest structure allocated by         |
 |                     CreateExtIO().                                   |
 |______________________________________________________________________|