23 Nov 2022

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Stuff to remember and try doing soon:

Put an index in README.
Try Jupyter again, or the Google Code thing.
DONE: Fix up sandpit repo, e.g. Connectorama and other uncommitted things.
Create helpers so that I can (say) link to my GitHub repos more easily in these notes.
Script to generate new journal entries.
Verilator. See 0050 and beyond.
Wokwi.
RP2040. Simulation using rp2040js (example).
Compare laptop sandpit repo with that on desktop PC, esp. re KiCAD projects.
PLL in Verilog and C simulation.
Diagrams (e.g. cabling) for IBM PS/1 FDD video. Why is pin 1 cut?
KiCad/PCB things to look into:
- How to include Edge Cuts in a footprint, or otherwise respect them when the footprint is placed.
- Purpose of layers:
```
Edge.Cuts
Margin
F.Courtyard
F.Fab
```
- Footprint libraries: MountingEquipment, MountingHole
- YouTube video on different PCB experiments:
  - Chip-in-hole mount
  - Test point holes (single and pair bridges) for clip probes
  - QFN soldering esp. centre heatsink pad -- try cut-out instead, for direct soldering?
  - Is it possible to make a PCB with holes that allow for vertical mounting of a VGA connector that uses solder cups? Or is the clearance too fine?
  - DSUB-37 x 2 as general array - breakout
  - Learn more about proper ways to do screw holes esp. for JLC.
  - PCB inductors and capacitors.
  - Vertical interfaces
  - Angular mounting
  - Mechanical interlocks -- puzzle edges or dovetails
  - Silkscreen and other feature size tests
- JLC PCB assembly service via LCSC

Random notes:

Diodes/LEDs:
- Typical diode breakdown voltage: -50V to -100V.
- Typical (silicon) diode forward voltage: 0.7V.
- LED forward voltages usually in the range 1.6~3.3V (lowest for red, often around 1.8V).
Python:
- My VM has python3 installed, but not python (v2).
- PIP is not installed, so: sudo apt install python3-pip -- Reboot after this because of kernel update message.
Renaming KiCad projects:
- There are scripts to do this; I've seen a python2 stand-alone vs. python3 pip.
- With my "Connectorama" project in KiCad 6, is it just a simple matter of find-and-replace for all filenames and file contents that refer to Connectorama?
  - I did this manually and it seemed to work OK.

IBM PS/1 FDD adapter

First version works fine. Possible improvements:

Project has been renamed manually from 'Connectorama' to 'ACUcard'.