There were four models of adaptor made for the 100 series PowerBooks, which differ in their power rating. Have a look at this article: http://support.apple.com/kb/TA32393?viewlocale=en_US. Although the connectors are the same, some adaptors are not universal and care should be taken particularly with the PowerBook 100 and 150, where an adaptor under 19W must be used. Although not completely logical in electronic terms, (the PowerBook should only draw the current it needs), higher powered adaptors can and do toast 100 and 150 models.

The 1400 adaptor should work fine with the Duos.

Very, very nice conquest by the way. SCSI hard drives for PowerBooks are also a good thing to have as they are diffucult to find these days.