Welp, it's happened: I've defended and filed for my PhD. Now I'm just waiting for the the final "ok" check boxes to be clicked and I'll officially be a doctor! Woohoo!
To be honest, it really hasn't hit me at all yet. It's been such a long road, and even the last few days of dotting "i"s and crossing "t"s have been long and non-trivial. But slowly and amorphously it's taking shape. Thank God, too. I'm not sure how much longer I could've gone on as a PhD student. It's utterly exhausting. I'm glad that this was the path that I've pursued, but would never EVER fault anyone for not going this route.
More fun though is that I've begun the work of getting the Kino74 back up and running and hopefully I'm going to make a few improvements along the way. The first thing to work on is rewiring things with a focus on making sure things are neat, clean, and not too dense. While the initial wiring worked ok, it just was never quite as nice as I wanted it to be. I used pre-cut jumper wires that always left extra wire sticking out, and after looking at all of these other projects that look so nice a neat, I think that would be a good first goal.
I started with the register board, pulling all of the wires out (truthfully, a little bit painful) until I was down to just the chips and then finally the bare board. I wanted to see if I could lay things out a little bit more efficiently and structure everything around a more central bus, rather than having the bus running down one side of the board. I rewired up the program counter and a 555-based clock signal to kick things off.
After a lot of fussing, I arrived at an organization that I didn't hate, and managed to fit all of the key registers onto one board. I'm using yellow wire for "data" lines (also for addressing).
After a lot of measuring and stripping wires, I managed to hook everything up, however after some initial testing I'm realizing that something is quite deeply wrong with what I've done. Haha. Like, it's real bad. I've been a little too preoccupied with PhD stuff over the last couple of weeks to do much more than test a couple of pins on each chip, get really flustered, and then give up for the night, but hopefully now that the major life stuff is out of the way and I have a couple of weeks of vacation I'll be able to sit down and somewhat more patiently go through element by element to try and diagnose exactly what is happening.
Tonight I finally got to work with my Teensy 3.2 that I picked up probably a little over a year ago. I'm going to build a rudimentary logic analyzer. Hopefully by carefully pulling the registers out of the board one-by-one I can track down the source of my grief. I'll use the teensy to monitor the bus lines while I debug. I'd like to eventually set it up so that the teensy can capture a trace and store it for later download (complete with a clock-based trigger, and reset, etc.). While not fast enough for general usage as a logic analyzer or oscilloscope, the Teensy should be pleeeenty fast for debugging this machine. I've decided that instead of trying to get it all programmed up front, I'm going to just work on developing the little logic analyzer as I go, and as I find I need more functionality.
Anyways. Gonna try and keep things up to date here a little bit better and post progress on the debugging and improvement of the Kino74!