Complex sentence: The modified slot is found only on the 5160 and 5155 Portable PC; it is not in the 5150, IBM AT, or any clone PCs. During this period, it was commonplace for ISA cards to include a jumper allowing them to work in Slot 8.
Split into simpler sentences: The modified slot is found only on the 5160 and 5155 Portable PC. It was commonplace for ISA cards to include a jumper allowing them to work in Slot 8.