Half-Ass Assembly...

A project log for WITCH-E Decimal Based Computer

Document and create a modern replica of the Harwell Dekatron computer known as the WITCH

Dave's Dev LabDave's Dev Lab 11/18/2017 at 04:390 Comments

Well.... sorta! The original WITCH computer ended up with 10 available storage locations, with each storage location having 10 addressable registers, however it didn't start that way. During the early prototype and development of the WITCH, there were only 3 storage locations available! With this in mind, I made similar design/prototype choices during Phase-2 of WITCH-E to only make 3 storage locations. Phase-2 also only supports four functions instead of the full 10 on the original WITCH. The four functions are: Add, Add with Clear, Subtraction, Subtraction with Clear. The Relay Set D Decode board needs to support the eventual capacity of all 10 storage locations so that is how I designed it, but at this stage, with only 4 functions, and 3 storage locations (with 4 registers each), there is no need to build up all of the support on the Decode board. I KNOW I will eventually have to make changes to the Decode board due to testing and debugging, so it just makes sense not to build up the full support and waste parts at this time.... Yeah... I know... it does look a little "Half-Ass" but hey, we can all try to be optimists and think of it as "room to expand"!