Was the ZX Spectrum better at handling than later PCs-keyboards without having diodes in its key matrix? I encountered this comment on Y Combinator but I fail to understand it.
Couldn't the Speccy method scale to 101-key keyboards and the like?
The ZX Spectrum in 1982 (and I'm quite sure its ancestors ZX-80 and ZX-81 from their eponymous years) had a keyboard just as cheap or cheaper, with a similar matrix arrangement), but had no ghosting at all:
Instead of having an "all hot" electrical configuration, it would cycle through the rows with a "one hot" configuration, and read the columns. If I recall correctly, it would be something like 20 cycles of a 4Mhz Z-80 to read one 5-column row (you'd need 8 of them to read the entire 40-key keyboard), and it was done every 50hz/60hz interrupt by the main CPU - modern keyboards have an ASIC on par or 100 times faster than a Z-80 just for the keyboard.