Computer Knowledge: Facts, Shortcuts, Conversions
What the section tests
Computer Knowledge checks everyday working literacy: hardware, operating systems, MS Office, internet and networking basics, databases and cyber safety. The paper is factual - definitions, shortcuts and abbreviations.
Core rules
- Memory hierarchy: registers, then cache, then RAM, then secondary storage (HDD/SSD). RAM is volatile; ROM is non-volatile and holds firmware such as the BIOS.
- Units: 1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB.
- Shortcuts: Ctrl+C/X/V copy, cut, paste; Ctrl+Z undo; Ctrl+Y redo; Ctrl+S save; Ctrl+P print; Ctrl+F find; Alt+Tab switch windows; F5 refresh.
- Excel: B4 means column B, row 4; $B$4 is an absolute reference; every formula begins with '='.
- Security: HTTPS encrypts traffic using TLS; a firewall filters traffic; phishing is a fraudulent message that harvests credentials.
Worked example
Convert 1011 in binary to decimal and then to hexadecimal. Place values from the right are 2⁰, 2¹, 2², 2³ = 1, 2, 4, 8. Bits set: 1×8 + 0×4 + 1×2 + 1×1 = 11. For hexadecimal, regroup in fours from the right: 1011 = 11 decimal = B. So 1011₂ = 11₁₀ = B₁₆. The 8-4-2-1 weighting answers most conversion questions in seconds.
Traps that cost marks
Calling RAM permanent; confusing ROM with RAM; saying a byte has 10 bits; treating 'www' as a protocol when HTTP and HTTPS are the protocols; and mixing antivirus (removes malware) with firewall (filters traffic).