Diagnostic Testing of Half-Duplex I/O Devices
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
This article describes an asynchronous, serial diagnostic arrangement especially suitable for testing half-duplex input/output devices coupled to a processor through an adapter interface. Peripheral devices to a computer system are usually coupled to the main processor via an adapter between the device drive interface and the system bus. Adapters have differing levels of intelligence; some adapters offer little more than read and write capability whereas others provide features such as buffering (to help separate the drive transfer rate from the system transfer rate), error retry, error correction, and multi-drive commands such as copy. Most adapters now include a microprocessor for interpreting high level system commands and controlling adapter operation.