Complex sentence: There is no strict limit to the number of PC/104 cards that can coexist in one system; however, as more modules are added, the stack height increases, and signaling requirements may not be maintained.
Split into simpler sentences: There is no strict limit to the number of PC/104 cards which can coexist in one system. However, as more modules are added, the stack height increases, and signaling requirements may not be maintained.