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HP-20B key matrix - Scott Newell - 07-20-2008 Appears to be a 6 row (rows are inputs) by 7 column (outputs) matrix, so it could have had up to 42 keys. The on key appears to be outside the matrix. (Pressing the on key takes TP11 to ground.)
Inputs:
Outputs: The matrix layout is pretty much what you'd expect, but with the rows running vertically and the columns running across the keypad. I've worked through it and can provide details if needed.
Couple of weird things. 2: I'm a bit surprised that the on key isn't using one of the wakeup inputs. (I'm sure that design choice will make more sense once I dig into the power management.)
Guess I need to find the analog inputs.
Re: HP-20B key matrix - cyrille de Brébisson - 07-21-2008 hello, since all ports are both input/outputs, rows and columns can be exchanged, so there is no 'row' 'column' like they were on the saturn. you got pretty much all the port wrong.. sorry. the ON key is on a wakup pin: the FWUP (of Fast Wakeup pin)...
regards, cyrille
Re: HP-20B key matrix - Scott Newell - 07-21-2008 Quote: Really? Weird, I even double checked my work on that one. I wonder...oh crap. I'll bet I forgot to switch to little endian mode. (OCD Commander likes to boot in big endian, even for ARM targets.) Grrr.
Sorry for the noise guys, I'll rework it tonight.
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