What the 75% picture shows
A 75% board keeps the function row and the arrows of a full-size keyboard, drops the number pad and packs the rest together with no gaps between key groups:
- A function row with Esc, F1 to F12, Print Screen and Delete.
- The full main block, with a shorter right Shift so the ↑ key fits under Enter.
- A column on the right with Home, Page Up, Page Down and End.
- A bottom row with Ctrl, Windows, Alt, Space, Alt, Fn and Ctrl, then ← ↓ →.
The list under this text shows what a full-size board has that this one leaves out. On most 75% boards, those keys (Insert, Scroll Lock, Pause, the number pad) either don’t exist or sit on an Fn layer, and any you press that way show up under Other keys detected.
Testing the knob
Some 75% boards put a rotary knob in the top right corner instead of a key. On the Keychron V1 the default firmware turns it into volume down and volume up, a press into mute, and the same turn with Fn held into lighting brightness. Turn it slowly, one click at a time, and watch the system’s volume display: each click should move it one step in the right direction, with no skipped or reversed steps.
The W3C’s list of key codes includes the volume keys, but browsers aren’t required to report them, and the operating system usually acts on them first. So a working knob may not appear in the tester at all; the system’s volume is the thing to watch. If you remap the knob’s press to an ordinary key in your keyboard’s software, it lights up or appears under Other keys detected like any other key.
Wireless 75% boards
Many wireless 75% boards, the AULA F75 among them, connect three ways: USB cable, a 2.4 GHz receiver and Bluetooth. If a key misses presses or repeats only in one mode, run the test once per connection. A key that works on the cable is a sound switch, and the problem is the wireless link: charge the board, plug the receiver into a port close to the keyboard and keep other wireless gear away from it.
What this layout leaves out
The keyboard above has 83 keys, and the score counts 82 of them (the dashed keys don’t reach the browser). The tester’s full-size layout has 104. These are the ones this layout doesn’t draw; if you press one through an Fn combination, it appears under “Other keys detected” instead of lighting up the picture.
- System keys: Scroll Lock, Pause
- Navigation keys: Insert
- Number pad: all 17 keys
- Other keys: Right Win, Menu