Re: mac quadra found

> On Mar 22, 2024, at 7:26 AM, Jim Spath <[email protected]> wrote:
>=20
> Hello!
> While emptying a friend's house, we found a Mac Quadra (among a number
> of IBM PC clones), and I thought maybe it would run NetBSD. As the
> machine has not been plugged in for years it seems, my first thought
> was to vacuum/dust it out before applying power. After that, what
> would I look for to check if NetBSD will run?

What model is it, specifically?  I'm pretty sure NetBSD will run on all =
of the Quadras; they all have a 68040 of some sort with an MMU (either a =
full 68040, or a 68LC040, which lacked the FPU).

Macs of this era are prone to electrolytic capacitor leakage, both the =
surface-mount electrolytics on the main logic board as well as the bulk =
through-hole electrolytics in the power supply.  The ones on the MLB are =
the most problematic as they can damage other components or traces if =
they've leaked.  It is probably a good idea to closely inspect the MLB =
before attempting to power it on.  This may require fully extracting the =
board from the machine.

Even if the elctrolytics haven't spewed all over the machine, it's =
probably a good idea to re-cap it, as those crappy electrolytics from =
the 90s WILL fail at some point.  The YouTube channel "Adrian's Digital =
Basement" has some great videos on recapping Mac MLBs, including ones =
that have had electrolyte leaked all over the board.  But, while Adrian =
uses ceramics to replace the electrolytics (it's convenience because =
ceramic caps are non-polarized), be aware that ceramic caps have =
different characteristics and may not result in the same capacitance =
when used in this way.  For this reason, when I replace surface-mount =
electrolytics, I use new surface-mount electrolytics, not =
same-capacitance ceramics.

-- thorpej