Does it have to be Linux? If not, there are several systems which are
supposed to be simpler than Linux and pedagogically interesting. For
example, VSTa (see on <URL: http://www.vsta.org/ >). It's GPL'ed.
Also, if you are interested in history, you might have a look at <URL:
http://www.sco.com/offers/ancient.html >: the Santa Cruz Organization
is offering free source licenses for versions 5, 6 and 7 of Unix
(circa 1970). The entire v7 kernel source code, for example is below
20klines (mostly C, and a bit of PDP-11 assembler), including device
drivers. You can even find PDP-11 emulators to run the thing and play
with it. (But you can't redistribute it.)
(If you want something old *and* free-as-in-free-speech, there's ITS.
I don't think anyone was able to make it run on modern machines,
though. Making a PDP-10 emulator is much harder than for a PDP-11.)
Happy hacking,
-- David A. Madore (david.madore@ens.fr, http://www.eleves.ens.fr:8080/home/madore/ ) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/