[GTALUG] mysterious restarts

[Lennart Sorensen]

On Thu, Jun 16, 2016 at 11:55:53AM -0400, James Knott via talk wrote:
> Data General Nova & Eclipse computers had a choice of AC power or
> various clock rates derived from a crystal.  The crystal wasn't all that
> accurate, but normally AC is.

It would be pretty accurate for sure.

> The Data General Nova predates microprocessors.  It was first build
> around 1969, IIRC.  The Eclipse, while a later generation, used the same
> basic I/O board, which included the RTC circuits, along with serial port
> for the console and ports for the paper tape punch & reader.

Yeah that would be old enough to such a thing.

> Incidentally, one thing I did was modify those boards from 20 mA current
> loop to RS-232 for the console and also replaced the fixed crystal
> serial port clock (you had to change the crystal to change speeds) with
> a baud rate generator chip that used a colour burst crystal to generate
> a variety of baud rates.  With the 2 mods, those boards moved from 110
> b/s Teletypes, to 9600 b/s CRT terminals for the console.

That's a nice improvement.

-- 
Len Sorensen