I have an AIR 486EI v2.21 486 motherboard, S/N appears to be AA0427310 and dated 1994. Closest revision I can find online is 1.2:
https://stason.org/TULARC/pc/motherboards/A/A … 86EI-REV-1.html
Not sure if this will be useful, but there is a rev2 manual linked here: http://www.win3x.org/uh19/motherboard/show/354
(I'm aware of course that manual revision =/= motherboard revision)
More results: http://www.win3x.org/uh19/motherboard/result/?name=486EI
Thanks for the info. Although not a perfect match for my board, it's very cool to see the original manual
