Standard Signaling Method for a Bidirectional Parallel Peripheral Interface for Personal Computers
|Publication Date:||21 September 2000|
This standard defines a signaling method for asynchronous, fully interlocked, bidirectional parallel communications between hosts and printers or other peripherals. A functional subset of the signaling method may be implemented on personal computers (PCs) or equivalent parallel port hardware with new software. This standard recommends new electrical interfaces, cabling, and interface hardware that provides improved performance while retaining backward compatibility with this subset.
This standard also specifies a format for a peripheral identification string and a method of returning this string to the host outside of the bidirectional data stream.
This standard was created because there existed no defined standard for bidirectional parallel communications between personal computers and printing peripherals. Pre-existing methods utilized a wide variety of hardware and software products, each with unique and incompatible signaling schemes. This standard was developed to provide an open path for communications between computers and more intelligent printers and peripherals. The availability of a standard bidirectional protocol will encourage the development of new peripherals that return significant data, as well as basic status, to the host.