Tom:
May be your card has a partition in Sector 0. If so, at the address $01C6 is a value of the sector where the Boot sector is.This value multiply by $0200, gives you the offset address where the "EB 90.." are located.
The PC and Winhex make this offset when you are reading the "logical " drive.
Greetings...
Ruben de la Pena