Hello there!

Diploma in Computer Science is normally a 3 year course with 6 semesters in total, so two semesters each year. The syllabus for second year of the diploma course has been provided below. Note that this is only to give you a general idea, your university's syllabus may actually differ by quite a bit.

Semester 3

• Data Structure
• Operating System
• Networking
• Object-Oriented Programming in C++
• Economics
• Workshop

Semester 4

• Computer Architecture
• Database Management System
• Linux O.S
• Multimedia Technology & Application
• Programming in Visual Basic
• Marketing Management

You can check out these sites to look for free pdfs of the books you need:

• https://freecomputerbooks.com/
• https://www.freetechbooks.com/
• https://www.onlineprogrammingbooks.com/
• http://freebookcentre.net/

I hope this helps! Good luck!