New RockPro64 Power Up Problem

[TRS-80]

Yeah, a PC power supply is surely overkill (and less efficient) but if you have them laying around...  I have had several SBCs since years now, and I progressed from using high efficiency Mean Well power bricks, to more recently using (still high efficiency) Mean Well DIN rail mounted power supplies to mount SBCs (mainly to get them out of the way, but also so far they are actually cheaper, and much higher MTBF).

If you are old Slackware guy, you probably enjoy tinkering with the lower level stuff.  Personally, I want something that 'just works' (and I am Debian guy) so I use Armbian.  And they can always use more guys like you who know what they are doing with the low level stuff.  OTOH I think there is at least one person trying to get a Slackware based distro going on SBC, I am sure you could find them with a forum search here.

Next time you get stuck on something, you may find the answer browsing Armbian source code / docs / forum in fact. I'm pretty sure that's how I originally found them, there are tons of great info there going back years. PostMarketOS also has a lot of good documentation, but they are more focused on phones (Armbian is more about SBCs). PMOS is also Alpine based (which is a bit strange, to me anyway).

Glad to hear you are having fun. These are such cool little devices.