November 05, 2013
The LPT interface (parallel): generally used to connect to the printer or scanner. The default interrupt number is IRQ7, DB-25 joint by 25 feet. There are three main types ofparallel working mode: mode 1, SPP standard. The SPP data is semi duplex one-way transmission, transmission rate is slow, only 15Kbps, but is widely used, usually set as default mode. 2, EPP enhanced mode. EPP uses two-way half duplex data transmission, its transmission rate, higher than SPP up to 2Mbps, there are manyperipherals using this mode. 3, ECP expansion mode. ECP uses bidirectional full duplex data ...