I&#x27;m starting a segment of STEM hardware to allow middle-school kids to learn digital logic design in an interactive, visual-tactile way, in order to build a basis for learning software.<p>My official product crowdfunding is still in preparation - meanwhile I committed to teach a class on March 12 so I&#x27;ve designed a smaller, crude version that will work for the purpose.<p>The device is a reverse-engineered version of the first programmable logic chips with the fuse matrices replaced by a diode matrix. Users express logic equations by placing diodes at matrix junction points - this provides a tactile experience and visual feedback.<p>The logic and-or trees thus created control latches whose outputs go back to the matrix. The user can create state machines this way - it&#x27;s microprogramming since the underlayment is hardware only. And it allows users to grasp how symbols can control physical structure.<p>My Patreon fundraising page for the temporary stopgap device is www.patreon.com&#x2F;lfelsenstein . The larger project webite is www.andorbit.com .<p>This will be an open project - I&#x27;m counting on others to develop courseware, peripherals and a web-based structure for mentoring support.