> Is anyone running Debian 11 on a processor older than Pentium 4?
I'm using Debian (currently stable, tho I often end up moving to
testing) on my Thinkpad X30, yes.
The Thinkpad X30 has a 1.2Ghz Pentium M processor which is i686 not i386. Did you upgrade the RAM from its origional 512MB.
The quality of support for this hardware has evolved over the years, but
in my experience Debian 11 is the first release that's clearly better
than all the previous ones (the previous "best version" for me was just
before the move to KMS, which introduced various regressions on this
hardware, and it's only with Debian 11 that I can again run this
hardware without any workaround or occasional annoyances).
> I ask because I would like to bump 32 bit OS support from i386 (1985)
> to i686 Pentium 4 and newer.
That would leave *very* few CPUs among those supported by `i386` but not
`amd64` :-(
Stefan