return to Fundamental Views

Interfaces exist between the various independent components of the DIDO and are therefore fundamental to the integration of DIDO components into a system. Bidirectional interfaces are defined between:

• hardware-to-hardware
• hardware-to-software
• hardware-to-human
• software-to-human

Hardware interfaces are how the outside world connects to physical devices such as disk drives, monitors, keyboards, internal buses, batteries, internet ports, cameras, microphones, and sensors. These interfaces are described by the mechanical, electrical, and logical signals at the interface and the protocol for sequencing them.¹⁾ Fortunately, most of these interfaces are integrated into computer nodes and do not need to be addressed here. For example, the data from the sensor can be considered an Immutable Data Object and thus sent through the node network, but the actual acquisition of that data is a detail for nodes to implement.

Refer to Section 2.2.1.1.1 Platform Interface for more detail on Hardware interfaces.

Software interfaces isolate the underlying complexity of functionality provided by a software product or package through the use of an Application Programming Interface (API). The end result of this is to treat software products or packages as opaque blackboxes.

Refer to Section 2.2.1.1.2 Software Interfaces for more details on this subject.

Human interfaces within DIDOs are bidirectional and primarily cover the software-to-human components. A software Application Programming Interface (API), although defining interactions between people and software, is classified as a software interface and not a human interface. Human interfaces cover the human interaction between the humans and an operational system; examples include mouse, keyboard, trackpad, and windows presented to users of the system.

Refer to Section 2.2.1.1.3 Human Interfaces for more details on this subject.