Your Mac won’t type U, I, O, J, K, L, and M? Here’s why

The vestiges of Num Lock remain in macOS in a newer feature, Mouse Keys.

mid 2018 macbookpro keyboard
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Glenn Fleishman is the author of dozens of books. His most recent include Take Control of Your M-Series Mac, Take Control of Securing Your Mac, Take Control of Zoom, and Six Centuries of Type and Printing. In his spare time, he makes Tiny Type Museums. He’s a senior contributor to Macworld, where he writes Mac 911.