Fact · Typing and writing speed
3keys
Wikipedia says keyboards without isolation diodes can produce ghosting effects when as few as three keys are pressed together.
Checked against its source on October 16, 2026
In the source's own words
“pressing as few as three keys can cause ghosting effects”
Key rollover (Wikipedia), Wikipedia, 2026, Key jamming and ghosting.
Open the original- What it measures
- The article describes these keyboards as matrix designs without isolation diodes that assume only a limited number of keys will be held down at once.
- What it does not show
- The article says the matrix is laid out so that common modifier combinations do not ghost. It does not say how many keyboards use this design today.