acer aspire 1640 bios -ati or uma how do i know which to use

Recommended by Wim's BIOS...

i downloaded the 3a19 bios from the acer site for an acer aspire 1640
aspire 1642 WMLi model ZL8
but I have a choice of two Bioses
ZL9A3A19 is for ATI and ZL9I3A19 is for UMA

i was tired and flashed the uma version which i think was wrong and i have some functionality but not all so i'm tempted to just flash the other but how do i tell before hand for future reference which is correct ( except when I googled uma i found that this might stand for upper memory area so excuse me for being dumb but do i flash both -- to me that doesn't make sense -- but don't ask and never learn)

do I need to open it up to identify the mobo? to help answer question above?

download and install CPUZ utility; tells mainboard type.