I really want to transfer my old Pokemon in emerald to my platinum cartridge..but... I have a DSi, and when I gave my brother my old ds lite...he lost it. It's been gone for a year now.... Is there any possible way to transfer my gen 3 Pokemon to gen 4 without a ds lite?
You can't do it without dual slots, sorry. You can only use a DS Lite and a regular DS to do so.
You need 2 DS systems to trade or you can ask a friend to help.