ncr/doc/Old Models/Technical Manuals/7453_... - Alsys Data

Chapter 4: Hardware Service 4-41Dual Port RS-232 Board (New Style)The Dual Port RS-232 Board provides two additional RS-232 ports perboard (in addition to the RS-232 ports provided on the Motherboard).You may use two boards in a workstation. Each board occupies an ISAslot, and each port requires an IRQ and a corresponding I/O addressspace. COM port assignments are made by way of hardware jumperson the board.AddressCOMA2783302E0378338238COMBCOMBIRQ3E82E83F82F8COMA3 4 5 6 7 9 10 11 12 15COMACOMBNote: The settings shown aboveand below are the default settings.These settings would strapCOMA as COM4: , and COMB as COM3: .The following chart is meant to show you how to interpret the possible strapping options using the defaultsettings as examples . When setting the address for COMA, connect a pin from the top row to a pin from thecenter row of pins on the address header for the address you want to use. When setting the address for COMB,connect a pin from the bottom row to a pin from the center row of pins on the address header for the addressyou want to use. When setting the IRQ for COMA, connect a pin from the top row to a pin from the center rowof pins on the IRQ header for the IRQ you want to use. When setting the IRQ for COM B, connect a pin fromthe bottom row to a pin on the center row of pins on the IRQ header for the address you want to use. To disableeither com port, do not install any straps for that port.AddressesIRQsAddress ----3302783782E02383382E83E82F83F8IRQ ---3 4 5 6 7 910 11 12 15COMACOMACOMBCOMB16009