HP 39gs and SD card

[matthiaspaul]

(01-05-2018 02:52 PM)Claudio L. Wrote:  

(01-05-2018 02:34 AM)matthiaspaul Wrote:  I haven't tried myself, does newRPL ignore the write protection switch? Doesn't sound like the best of ideas to me then...

newRPL does honor the write protection switch.

Great, thanks, I misred rcpdvc's statement. Obviously, he just found that the #WP line does not need to be weakly pulled down to GND. However, I would advise against not populating R67, in particular if the signal would go straight to the controller. (He does not state so, but readers could get the impression that, if it seems to work without R67, the resistor might not be needed at all.)

Charge may build up depending on various conditions and open inputs do not necessarily hold "low" all the time. Also, if the voltage level happens to float in the middle region between VCC and GND, this may increase the CMOS controller's power consumption considerably (even if the calculator is switched "off").

Greetings,

Matthias