David Empson wrote:
There are four ROM chips in the platinum IIe, which is the same number as in other models of the IIe. Two of them contain the firmware which appears in the $C100-$FFFF memory region. They are labelled "CD ROM" and "EF ROM" on the logic board (or something similar).
Maybe the European model was different but the north american version of the platinium IIe only had 3 ROM chips. The CD and EF ROMs were replaced by a single CF ROM. You can download a pic of a platinium motherboard from my website http://homepage.mac.com/waynes