The Terminal Interface Message Processor Program.

摘要

Understanding the Terminal IMP software depends on an understanding of the hardware environment in which the software resides. A summary of the Terminal IMP hardware follows. Up to 63 terminals, either remote or local, of widely diverse characteristics may be connected to a given TIP and thereby 'talk' into the network. It is also possible to connect a Host to a TIP in the usual way a Host is connected to an IMP. The TIP is built around a Honeywell H-316 computer with 28K of core. It embodies a standard 16-port multiplexed memory channel with priority interrupts and includes a Teletype for debugging and program reloading. Other features of the standard IMP also present are a real-time clock, power-fail and auto-restart mechanisms, and a program-generated interrupt feature. As in the standard IMP, interfaces are provided for connecting to high-speed (50-kilobit, 230.4-kilobit, etc.) modems as well as to Hosts. Aside from the additional 12K of core memory, the primary hardware feature which distinguishes the TIP from a standard IMP is a Multi-Line Controller (MLC) which allows for connection of terminals to the IMP. Any of the MLC lines may go to local terminals or via modems to remote terminals.