8-bit CPU: Wiring and testing the new ALU
Once I had soldered the boards I was eager to test them. At first I "poked around" using jumper wires and boards appeared fine. To be absolutely sure, however, I have to wire them together into a new ALU block and hook it up to my Arduino testing device. Boards are a bit elevated above the breadboards, so it seemed to be a good idea to run wires underneath the PCBs. To save on wiring, I opted for simple, fixed configuration (same as breadboard prototype and Ben's original), instead of my new, dual-output feature. I tested the dual-output some time later, adding jumper wires for missing connections. The concept works fine, but it takes 14 control wires to tame the beast. This will have to wait for proper control logic. The ALU block is not the only piece that is new. My new EEPROM writer features additional pin sockets, giving access to onboard shift register outputs. When no EEPROM needs to be programmed, it can be repurposed to switch control lines. I do not need my ad-h