Legacy Control units run XP (not sure it really was embedded), as far as I am aware all Core units run a version of Linux tailored for small footprint applications such as NAS and Sooloos core duties.

However, MC600 was a big beast so may have run something more powerful, like XP.

imho, still room in Meridian lineup for a Meridian badged and supported NAS solution, in the same way that there is for a control unit. Which leaves a CD ripper - still think the 808 is the solution, rip while you listen. Of course, for some ripping is oh so 2012 what with downloads and streaming now.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).