The following are pre-computer age of 19th century except*1 pointabacusnapier's boneside ruleLaptop

The question asks which of the following items does not belong to the pre-computer age of the 19th century. Let's analyze each option:

1. Abacus: An ancient counting tool used for arithmetic calculations, definitely predating the 19th century.
2. Napier's Bones: A manual calculating device created by John Napier in the early 17th century, also predates the 19th century.
3. Slide Rule: A mechanical analog computer invented in the 17th century, commonly used in the 19th century for calculations.
4. Laptop: A portable personal computer that was developed long after the 19th century, specifically towards the end of the 20th century.

Conclusion

Based on the analysis, the item that does not belong to the pre-computer age of the 19th century is the Laptop. This is the only option that is a product of the modern computer age.