Procrastinated on actually putting together a MiniDragon acrylic board by updating the layout KiCad file to include the upcoming adder circuit. Neat, the documentation is now more up-to-date than the actual CPU.

https://github.com/dragonMinded/minidragon

#MiniDragon

Tonight, instead of doing another bring-up stream, I focused on a tedious but important task on the MiniDragon: identifying and labeling the MSB/LSB on each bus connector. And by that, I mean the most significant bit, and least significant bit. Most of the components are bit-order agnostic. As long as you output the same order you input, they'll work. But, now that everything is piped together, there needs to be an agreed-upon bit order! So, I did that!

I do have some old physical layout documentation that dictated my conventions at the time, and I've verified those are upheld. But, the labels are way easier to read and see.

#MiniDragon

dfghdoihgdoifghdifogh the ALU is WORKING.

#MiniDragon

Brought up two more 2-bit adder boards tonight on stream. After testing them individually I tied them to the existing two for shiggles. Behold, a 8.5" by 7" stack of boards that adds two 8 bit numbers with carry in and carry out. I got 4 more to bring up at some other point to have a functioning 16 bit adder, which I need in order to do indirect addressing and manipulate the instruction pointer and stack pointers (relative jumps, moving the stack pointer forward or reverse by an immediate or the A register, etc) and have arbitrary access to all 64K of memory.

#MiniDragon

tonight's meditative assembly was a bunch of distributor boards that i need for future panel layouts. the only components on any of these that aren't just pin headers are a bunch of capacitors on the power distributor boards. still, they make wiring boards to each other much easier and give things a bit of polish.

#MiniDragon