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   Bernie (codewiz@mstdn.io)'s status on Tuesday, 17-Dec-2024 04:03:07 JST Bernie

   in reply to

   Meanwhile, I also checked the reset logic, which I suspect to be quirky.

   The A3000 uses a PST518, a small 3-legged IC which looks like an ordinary transistor, but monitors the +5V power line to assert a _FAIL signal when it's too low.

   This capture shows what happens when the power supply is switched off: _FAIL (above) drops sharply when +5V (below) falls below 4.4V. Looks good.

   #electronics #vintagecomputing #amiga