This board helps test floppy drives of several different types:
The board basically breaks out every signal to a control switch, indicator LED, or test point. It's not designed as a flux imaging tool--it's just a simple way to exercise features of a floppy drive.
There is an optional section of the board that is a step controller for the head stepper motor. This controller has an encoder wheel and a small 7-segment display. It will let you select and automatically step to a particular track.
Uses an ATmega328PB microcontroller as its CPU.
A troubleshooting cheatsheet for the Commodore 1541 floppy drive.
Like a CTF, but for sysadmins. They give you a server with at least one problem; troubleshoot and fix it. Great practice for tech interviews.
Turn a Raspberry Pi into an oscilloscope. Probes attach to the GPIO pins.
Repairs that you can carry out at home on bricked iPods.
A massive online database of default passwords for networking hardware, embedded devices, and operating systems.
How to debug removable devices under Linux with the Gnome desktop.
An excellent blog post on what to do if your MySQL database server isn't working right because an InnoDB table has been corrupted. I've used this process myself and it works like a charm. Knowledge of MySQL in particular and RDBMSes in general is required.
How to enable a CUPS printer that says it's disabled.
/usr/bin/enable <name>
or /usr/sbin/cupsenable
/usr/bin/disable <name>
or /usr/sbin/cupsdisable