http://pcenginefx.com/phpBB/viewtopic.php?t=421 some EGM articles on the SuperGrafx - and the very earliest reports (in english) that I am aware of on the PC Engine successor, PC Engine-2 ...before it was named SuperGrafx.
Ah, the memories! I have most of those mags and can still recall my excitement when reading about the SGX for the first time waaaay back when!
I have such great memories of those days...summer 1989 through summer 1990, ahhh. btw, the pages was updated with a few more articles.