Thanks rubber_jonnie. I substituted the reset switch from the FM for the sake of testing as a temporary measure and the results have got me a little confused. Voltage on pin 8 is 5.03v but voltage on pin 3 is 0v until reset is pressed then it reads 4.57v. I expected to see 5v and 0v when reset was p...

Taken a while to get time to work on this ste as I'm dealing with health problems which seem to take up any spare moments I have. Managed to do all the above that exxos and rubber_jonnie suggested. Voltage readings on Pin 3 of the 555 chip were strange and intermittent so decided to remove the reset...

Thanks rubber_jonnie will check all that over the weekend . I'm fairly sure I did get the jumpers for Tos right, the site you linked looks great so I'll check there as well.. thanks again.

Thanks for the welcome and the reply.. will try that next opportunity I get .. cheers

Hi all, new to the forum and finally worked up enough courage to ask some questions. Joined a few weeks ago and have been reading/studying all that I can about the Atari st (when I can spare the time) and have learnt a fair amount from the wisdom of the posts and guides here. Atari st was my first c...