Device Control From Process Space

Chapter 4: User-Level Access to Devices
How a user-level process can access and control devices on various buses.

Chapter 5: User-Level Access to SCSI Devices
How a user-level process can execute commands and transfer data to a SCSI device.

Chapter 6: Control of External Interrupts
How a user-level process creates or responds to external interrupt signals in the Challenge and Power Challenge systems.

Chapter 7: User-Level Interrupts
How a user-level process can trap and respond to device interrupts with low latency and the fewest context switches.