Full Duplex CRT and Teletypewriter Driver.

摘要

The full duplex CRT and TTY driver runs under Interdata's Real Time Operating System. The following enhancements are obtained with the full duplex driver over current CRT and TTY drivers. The driver is reentrant and controls many CRTs and TTYs of differing types,because device-dependent information is kept in the device's control block. Input and output is separate (full duplex requires a PASLA interface). The system console may be assigned to any device controlled by this driver. The driver standardizes control characters by handling them internally (such as delete character,etc.). The driver allows a calling task to write a prompt character and read in one indivisible step. The driver allows a carriage return-linefeed after a write to be suppressed. The driver handles the writing of nulls before each line to devices requiring them.