MXV11-B Multifunction Option Module

From Computer History Wiki
Revision as of 11:57, 26 August 2024 by Vaxorcist (talk | contribs) (Section "Boot ROM usage" added)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

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.

Boot ROM usage

You can use the MXV11-B2 ROM chip set (23-145E4-00 / 23-146E4-00) to convert the MXV11-B into a boot module for QBUS PDP-11s capable of booting:

See also

External links