ri ps ▁around ▁the ▁connect ors ▁to ▁key ▁both ▁pl ugs ▁and ▁so ckets ▁so ▁the ▁flat ▁side ▁has ▁a ▁specific ▁relation ▁to ▁the ▁shell ▁key way , ▁but ▁this ▁feature ▁was ▁ignored ▁by ▁some ▁third - party ▁manufact ur ers . ▁Additionally , ▁there ▁are ▁four ▁ways ▁to ▁orient ▁the ▁receiving ▁socket ▁on ▁a ▁device ▁such ▁as ▁a ▁keyboard ; ▁various ▁Apple ▁key boards ▁use ▁at ▁least ▁three ▁of ▁these ▁possible ▁orient ations . ▁ ▁The ▁mini - D IN ▁conne ctor ▁is ▁only ▁r ated ▁for ▁ 4 0 0 ▁insert ions ▁and ▁it ▁is ▁easy ▁to ▁b end ▁a ▁pin ▁if ▁not ▁inserted ▁with ▁ca ution ; ▁in ▁addition , ▁the ▁socket ▁can ▁become ▁loose , ▁resulting ▁in ▁inter mitt ent ▁function . ▁ ▁Some ▁Apple ▁Des ktop ▁Bus ▁devices ▁lack ▁a ▁pass - through ▁conne ctor , ▁making ▁it ▁impossible ▁to ▁da isy - chain ▁more ▁than ▁one ▁such ▁device ▁at ▁a ▁time ▁without ▁obsc ure ▁split ter ▁units . ▁Key boards , ▁software ▁d ong les , ▁graphics ▁table ts , ▁game ▁p ads ▁and ▁jo yst icks ▁typically ▁have ▁pass - through ▁connect ors , ▁while ▁few ▁m ice ▁or ▁track ball s ▁have ▁them . ▁ ▁One ▁peculiar ity ▁of ▁Apple ▁Des ktop ▁Bus ▁is ▁that ▁in ▁spite ▁of ▁being ▁elect r ically ▁unsafe ▁for ▁hot - sw apping ▁on ▁all ▁but ▁a ▁few ▁machines , ▁it ▁has ▁all ▁of ▁the ▁basic ▁capabilities ▁needed ▁for ▁hot - sw apping ▁implemented ▁in ▁its ▁software ▁and ▁support ▁hardware