My first computer growing up was a 486 Baby-AT computer put together by a local Perth company, Trinix computers (who now appear to be a Managed IT company). It was based on an ECS AL486 motherboard, for which there appears to be very little information floating around.
Since I still have the computer, and all of the physical manuals, I've scanned in the motherboard manual. Hopefully it'll be of use to someone!
The BIOS refers to itself as:
PhoenixBIOS Version 4.03 Copyright 1987-1994 Phoenix Technologies Ltd., All Rights Reverced. AL486 V1.1 6/26/1994
However, the last few bytes of the BIOS image appear to contain the date 06/21/94, and the identification bytes FC and FB.
And bonus points for anyone who can find JP42 on the schematic on page 13. It's listed in the cache jumper settings on page 11, but doesn't appear to actually exist — let me know if I've just missed it!
Cheers,
— David
Update: This has now been uploaded to the VOGONS Vintage Driver Library.