On 06/18/2020 03:14 PM, Peter Van Peborgh via cctech wrote: Sure looks like Control Data, a major manufacturer of mainframe computers in the 60's and 70's. And, being all discrete transistors, that would likely be late 60's. Jon

Hi Peter, That is a stunning board, and in beautiful condition. The square cubes are transformers, most likely some sort of pulse transformer on the base of the transistor. A multimeter will tell you in quick form. Doug Kindest regards, Doug Jackson em: doug at doughq.com ph: 0414 986878 Check out my awesome clocks at www.dougswordclocks.com Follow my amateur radio adventures at vk1zdj.net ----------------------------------------------------------- Just like an old fashioned letter, this email and any files transmitted with it should probably be treated as confidential and intended solely for your own use. Please note that any interesting spelling is usually my own and may have been caused by fat thumbs on a tiny tiny keyboard - for this I apologise in advance - It's ok bec**** we don* nee* accu**** tex* to unde****** actu** mean***. Should any part of this message prove to be useful in the event of the imminent Zombie Apocalypse then the sender bears no personal, legal, or moral responsibility for any outcome resulting from its usage unless the result of said usage is the unlikely defeat of the Zombie Hordes in which case the sender takes full credit without any theoretical or actual legal liability. :-) Be nice to your parents. Go outside and do something awesome - Draw, paint, walk, Setup a radio station, go fishing or sailing - just do something that makes you happy. On Fri, Jun 19, 2020 at 6:14 AM Peter Van Peborgh via cctech < cctech at classiccmp.org> wrote: