Model 10BACIA Auxillary Computer Interace Card
This card permits any System 10 "B-sized" mainframe to establish simultaneous high-speed communications with more than one external RS232 device (computer, terminal, buffered printer, recorder, etc.).
Each 10BACIA supplies an independent "auxiliary" full-duplex RS232 interface, operating with its own user-specified "protocol" characteristics. The number of 10BACIA cards a mainframe may contain is limited only by the number of available "B Slots".
As seen by a connected external RS232 device, an "auxiliary" interface port behaves identically to the mainframe's standard Computer Interface Port. That is, a standard mnemonic command issued to a 10BACIA by the connected device will invoke a response identical in form to that produced by the Computer Interface Port to the same command.
While the activity of a given "auxiliary" interface port can be directly controlled by the external RS232 device to which it is connected, it can also be controlled by commands entered through the mainframe's plug-in keyboard or Computer Interface Port.
The Model 10BACIA is a system COPROCESSOR. In addition to an auxiliary RS232 interface, it also provides an on-board DATA RAM. Externally acquired numeric and logic data can thus be downloaded from the connected RS232 device to the 10BACIA itself. With each internal scan cycle, this data will be locally updated (at the 10BACIA) and will be read from there by the system Central Processor. Such local handling of downloaded data by the 10BACIA helps preserve the mainframe's high scan speed when a large number of inputs is involved.
Front-edge LED status indicators similar to those on the mainframe's Model 10BIP232 Interface Card let you monitor line and command activity at each auxiliary interface port. In addition, a 10BACIA's COM indicator will light when that card has been designated to be the mainframe's "Default Communications Port."