Date   : Sun, 31 Jul 2005 08:16:46 +0100
From   : Mike Tomlinson <mike@...>
Subject: Re: clock box

In article <1A84EB13D4F94A3BB02EF9D39FF80477.MAI@...>,
BeebMaster <beebmaster@...> writes

>It looks like the clock speed is
>fixed at 115KHz.

There's no significance in the fact that the output from the 555 is
connected to the "15k" jumper hole. It was just a handy spot for the
modifier to connect to the input of the 75159 line driver.  The clock
speed will be determined by the components soldered to the pins of the
555 chip.

I'd think the output waveform would be a square wave, which isn't the
most efficient way to clock an Econet, but will work if it's fairly slow
and the total network cable length is short enough.