you can consider visiting NAM-IP, a recent computer museum near
Namur (about 50km South of Brussels)
NAM stands for "Numerical Artifact Museum" but is close to name of
the hosting city
there are also some artefacts related to Multics
website is only French and Dutch but English booklets are available
with QR code scanning
guided tours may also be organised (contact
animation@nam-ip.be or me to see if possible)
I also plan to attend FOSDEM (the history track among others ;--)
Happy FOSDEM for those attending (physically or remotely) !
Christophe