nitro2k01 wrote:
That looks weird. 1) How the power seems to rise linearly rather than converge exponentially. (Capacitor charge curve.)
I have to assume it's an artifact of the flyback converter used inside the DMG. Evidently the flyback counts as a constant-current source charging a capacitor, hence the linear rise.
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On a DMG (unless I've missed something!) the only things connected to the reset line are the CPU, a pull-up resistor and the cartridge bus. To get a rise time of 50 ms, there would have to be a ~100 nF capacitor present, which afaik doesn't exist on the board
... now that's a very good question. I think your math is a little off (the time constant looks to me like it's somewhere around 15ms, so it's an unexplained 13nF, but 13nF is still too big to be plausibly on-die in late 1980s technology)
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but might exist on some cartridges?
I did this test without a cart.