Front panel switches - what did they do?

[Swift Griggs]

On Tue, 24 May 2016, Jon Elson wrote:
> The early PDP-11s had a diode matrix ROM for the boot memory.  You could 
> change the boot code with a wire cutter and soldering iron.

Is that similar to "wire wrap" ? I remember my grandmother talking about 
having to snip wires connected to diodes. I think this was in the 50's but 
it might have been the 60's, too. She mentioned something like that. 

-Swift