Unicode vs Code pages

[Chris Kavanagh]

Hello, Please pardon my ignorance on the subject ...   I was wondering if someone could direct me to some (highly) technical documentation of how code pages work, in particular to Windows systems?  I want to research/understand, exactly why there is still a need for code pages given the existence of Unicode.    I have just started a full time position, fresh out of university, that requires me to research localization on windows ce platforms.  If this platform is Unicode based, why is there a need for code pages?   I understand that code pages provide mappings of user inputs, but if everything is Unicode, why is this necessary - since all characters in Unicode are unique!   Information pertaining to the complete process, from input to font display would be greatly appreciated.   I have been researching this and still do not have a solid answer, only parts.   Thank you, Chris