PDP-11/10 console (was: DEC keys and consoles)

From: PDP11 Hacker ..... <ard_at_siva.bris.ac.uk>
Date: Mon Aug 4 15:01:50 1997

>There is what appears to be an RC clock composed of a 4.7 nF capacitor and
>a multi-turn trimmer potentiometer in the upper left corner of the M7260
>data path board in my 11/10. It looks like this clock feeds a 74197
>counter, which has a 5-position rotary switch connected (presumably for
>selecting what the incoming clock is divided by). I'll put a scope on pin
>40 of the UART after I power the machine up to see what effect the rotary
>switch has on the UART clock. It seems likely that the rotary switch is
>used for making large changes in the baud rate and the trimmer is used for
>tweaking.

If that's the board I think it is, it's an 11/10S. The preset was adjusted at
the factory, and you could set most standard baud rates using the switch. It
can't hurt to measure the frequency, of course.

I can check the printset next weekend for you if you can't figure it out.

>
>--
>Scott Ware s-ware_at_nwu.edu

-tony
Received on Mon Aug 04 1997 - 15:01:50 BST