NEC POWERMATE VE - SERVICE MANUAL 08-1996 Service Manual

Also see for PowerMate V100e: Service manual

Contents

NEC POWERMATE VE - SERVICE MANUAL 08-1996 Service Manual Manual pdf 25 page image

Technical Information 1-13Parallel InterfaceThe system has a 25-pin parallel bidirectional enhanced parallel port on the system board.Port specifications conform to the IBM-PC standards. The port supports EnhancedCapabilities Port (ECP) and Enhanced Parallel Port (EPP) modes for devices that requireECP or EPP protocols. The protocols allow high-speed bidirectional transfer over a parallelport and increase parallel port functionality by supporting more devices.The BIOS has automatic ISA printer port sensing. If the BIOS detects an ISA printer portmapped to the same address, the built-in printer port is disabled. The BIOS also sets thefirst parallel interface port it finds as LPT1 and the second port it finds as LPT2. Theinterrupt is selected to either IRQ5 or IRQ7 via Setup. Software selectable base addressesare 3BCh, 378h, and 278h.I/O addresses and interrupts for the parallel port are given in Table 1-7.NOTE: Any interrupts used for the built-inparallel port are not available for ISA parallelports.Table 1-7 Parallel Port Addressing and InterruptsStarting I/O Address Interrupt Level Port378 IRQ05 LPT1278 IRQ05 LPT1 or LPT23BC IRQ07 LPT1 or LPT2378 IRQ07 LPT1278 IRQ07 LPT1 or LPT23BC IRQ07 LPT1 or LPT2Parallel interface signals are output through the system board’s 25-pin, D-subconnector.The connector is located at the rear of the system unit. Pin locations for the parallelinterface connector are given in Appendix A.Serial InterfaceThe system has two 16C550 UART compatible serial ports (COM1 and COM2) integratedon the I/O controller. The serial ports support the standard RS-232C interface (seeTable 1-8). The buffered high-speed serial ports supports transfer rates up to 19.2 KB.These ports allow the installation of high-speed serial devices for faster data transfer rates.