MXV11-B Multifunction Option Module

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The MXV11-B Multifunction Option Module is a QBUS dual-height peripheral board (M7195), intended to allow the creation of complete systems in a minimal-sized QBUS backplane. It is very similar to the earlier MXV11-A Multifunction Option Module, except that it is a Q22 device.

It contains two asynchronous serial lines (using the DL11 programming standard), an optional clock, a block of main memory, and some PROM for bootstrap purposes. The serial lines are connected via 10-pin Berg connector headers on the top edge of the card, using the standard DEC asynchronous serial line pinout, and line 1 can be set to halt or boot the machine on a break.

The clock is program compatible with the KW11-L Line Time Clock, but it is not a line time clock, since it cannot be driven from AC wall power; it can be connected to 50Hz, 60Hz, or 800Hz clock signals from a divided-down 20MHz crystal which is also used to provide the clock to the serial lines.

The board contains 128Kbytes of RAM; it can hold a pair of 2, 4, 8 or 16KB ROMs.