The Amiga system devices are software engines that provide access to the
Amiga hardware.  Through these devices, a programmer can operate a modem,
spin a disk drive motor, time an event, speak to a user and blast a
trumpet sound in beautiful, living stereo.  Yet, for all that variety, the
programmer uses each device in the same basic manner.

                        Amiga System Devices

 audio         controls the use of the audio hardware
 clipboard     manages the cutting and pasting of common data blocks
 console       provides the text-oriented user interface.
 gameport      controls the two mouse/joystick ports.
 input         processes input from the gameport and keyboard devices.
 keyboard      controls the keyboard.
 narrator      produces the amiga synthesized speech.
 parallel      controls the parallel port.
 printer       converts a standard set of printer control codes to printer
               specific codes.
 scsi          controls the small computer standard interface hardware.
 serial        controls the serial port.
 timer         provides timing functions to measure time intervals and send
               interrupts.
 trackdisk     controls the amiga floppy disk drives.

 what is a device?                             i/o request completion 
 accessing a device                            ending device access 
 using a device                                devices with functions 
 synchronous vs. asynchronous requests         example device programs