Effective realization of Kermit's microcomputer potential
Mark B. Johnson · 1986
In recent years the proliferation of microcomputer communication possibilities has been tremendous, and, as a result, the microcomputer is now reaching beyond its once solitary limits.With Kermit, one has the potential to better exploit the power of micros -from full-screen terminal emulation with mainframes to shared computing resources among different machines and operating systems.Limited only by the imagination, the list of Kermit's possible applications is endless.With the ever-increasing number of microcomputers and their distributive computing power, there is also an increasing need for communication to exploit this power.Without the ability to communicate, the microcomputer is severely limited to its proper peripherals and capabilities, like a child who cannot yet speak.But add communication, and the microcomputer, like a child after its first words, discovers a world beyond the horizon -a world from which it can benefit.Considering the variety of microcomputers and their similarities with each other and with minicomputers and mainframes, one realizes that the asynchronous serial line is the only standardized communication medium available across the gamut.Since the standards for both hardware and software are so widely adhered to, connecting two computers via their serial ports, whether by null modem, dial-up, or leased line, is probably the easiest and least expensive method of allowing them to communicate.Unfortunately serial lines have an inherent absence of safeguards for insuring data integrity.If no action is taken to counteract noise, loss of synchronization, and line outages, they will corrupt the data and render the communication useless.Thus something more than just connecting the computers is needed, and that something is a communications protocol.For two computers to transfer data they need to know something about it and about the way in which they are to transfer it.This is referred to as control information, and it generally includes some type of synchronization marker, a length indicator, a file pointer, and a checksum.With Kermit this control information is sent with the actual data, usually preceeding and