[TUHS] UNIX "Machine Layer"

[Roderick Bartlett via TUHS]

I believe the async lines were connected to I/O boards in the Front End Processor, AKA the Datanet 66xx.  I don't recall having to change baud rates that way but we did have to do periodic FCOs (field change orders) which required wiring changes and occasional chip changes to correct bugs.  I've still got my hand wire wrap tool somewhere but it hasn't been used in at least 30 years.

 - Rod

> On May 1, 2023, at 2:12 PM, Steve Simon <steve at quintile.net> wrote:
> 
> 
> “soldering iron…”
> 
> i do remember the fun of changing the baud rate of an async line on the Honeywell level 66 mainframe at college. This required shutting the whole machine down, removing one of the cards, and the (very careful) use of a wire wrap tool.
> 
> -Steve
>