Hey Folks
As some of you may have realized, I want to turn a keyboard into a JIS to experiment with a different layout.
Looking carefully at the PCB of my CM QFR, I notice there are a few missing diodes.
Pictures are poor but I'll retake them again if anybody wants to join in the hunt. I notice specifically:
1) some diodes related to JIS keys are soldered in and some are missing. IE this is a rather inconsistent manufacturing process.
2) Some diodes relating to ANSI and JIS keys are missing.
For instance,
ONE
Ctrl-L, K14. It is missing a diode. I suspect the two holes on the bottom left of the PCB were meant for the diode until the manufacturers realized the keyboard can't be placed into its casing with the diode in place.
TWO
Alt-R, K36. It seems to have been mismarked as Alt-R when it is actually Win-R which is not marked on this PCB.
THREE
The real Alt-R is marked J133 like a JIS key, and it lacks a diode. I have been able to use this keyboard pressing Alt-R and two other keys though. (To run some macros.)
FOUR
Backspace is labelled K78 on the PCB and the corresponding diode, D78, has been soldered in. But the actual switch is located at K101 where the switch solder took place. So is there a diode for backspace or not? Was backspace operating without a diode and won't function with NKRO? Except that a user wouldn't have known, because you normally don't press other keys and backspace at the same time?
I also have a question. If I want to 'activate' the JIS keys reliably, do I need a diode in each of the holes associated with the JIS key? Using the 'bridging the PCB contacts method' that some geekhackers have advised, I have found that the JIS keys do register under autohotkey even when the diode associated with them is missing. But if I want to use them to run macros with more than two keypresses (eg JISkeyx-A-B) do I need a diode?
To be safer rather than sorry (don't want to assemble an entire keyboard and find that some keys don't work) can I just put one diode in each available hole, regardless of whether I want to use that key? I think it's better than hunting for the correct diode slots because the markings don't always seem reliable. But I am also concerned that may lead to problems not foreseen because I lack the knowledge.
I am asking all these questions because I'm tryin to figure out how diodes work and how they fit into the scheme of things. Thanks for your patience!