Display terminal with modularly attachable features
US4271479A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1977 |
| Grant date | Jun 2, 1981 |
| Priority date | — |
| Expiry date | Oct 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/4213
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a display system having one or more display terminals, each of which includes a base unit which acts as a display and supports a keyboard for operation as a keyboard/display terminal, the terminal in turn interfacing with a plurality of features connected thereto. The features can be quite independent of the display, such as a card reader, or can be an operationally integral part thereof, such as extended capacity buffer operating jointly with the main buffer of the display, or can be interactive with the display, such as a selector pen or program function keyboard. The base unit and the features receive transmissions from a controller via a feature bus-out in the base unit and transmit to the controller via a feature bus-in in the base unit. The base unit also provides priority control in permitting features to respond to a controller poll. Commands are also directly addressable to the base unit and features by the controller, with the base unit performing interface functions between the controller and the features such as parity checking and time out error reporting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.