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Old 28th Mar 2021, 11:43 pm   #118
ortek_service
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Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
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Default Re: The Transam Triton Personal Computer

I'd assumed they all just switch on or off, when magnet was close-enough.
And so would give an out as log as a key was held down.

But maybe there was some extra circuitry in these that did debouncing by providing a fixed length pulse, rather than the main keyboard IC having to do this.
Or maybe it was to overcome issues with multiple keys being held down and the 2 of N system - as I can see that if you hold 2 keys down in different row & columns at the same time and these are all pulled to ground, then it would appear to controller that 4 keys would be held down on these rows and columns. Whereas a scanned-matrix system wouldn't have this issue, by only making one row etc. active at a time.

So I guess it's a case of doing some test on a working existing keyswitch, to establish exactly what it does.
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