sybok
Hi @ydek,
if antiX-21 does not support SiS Chipset, then I (*wildly*) guess you could start with the pseudo-antiX-19 bet3.
1) Install it.
2) Then disable upgrade of some packages.
Not quite sure which ones, it is possible it was already done when creating the ISO you have mentioned.
I expect that such modifications would be stored in the folder ‘/etc/apt/’, probably ‘/etc/apt/preferences.d/’.
You may try to politely private-message author of the ISO and ask whether this step is a feasible and a reasonable thing to do.
3) Modify repositories to antiX-21 and attempt to upgrade your system with these restrictions.
It either works or it does not.
Comment:
C.1) The assumption in item no. 2), fixing version of some packages saves the day, may not be valid.
Perhaps @anticapitalista or someone else has much more insight to know it and they can save you time attempting my above suggestion.
I have now idea if the not-supporting is due to kernel or some other packages, e.g. Xorg.
C.2) Even if it works, I am afraid that such a system will most likely break or phase out of upgrades in the future due to failed dependencies.
(The packages held back become too old and fail to provide an acceptable dependency for packages that require them [in newer versions], thus blocking these packages as well at certain versions.)
Related post (found as follows: log in, load Xecure’s profile, find corresponding engagements, browse the pages) you may have already found:
http://www.antixforum.com/forums/topic/how-to-use-antix-on-computers-with-a-motherboard-with-sis-or-via-chipset/
Even though my post might not have been very helpful, good look with your effort!