Basic Computer Knowledge
Basic Computer Knowledge covers hardware, memory, operating-system housekeeping, MS Office shortcuts and safe internet use. These are the day-to-day operations a laboratory attendant performs when recording results, emailing reports or printing labels.
Hardware and memory
- Input: keyboard, mouse, scanner, barcode reader. Output: monitor, printer, plotter.
- RAM is volatile working memory; ROM is non-volatile firmware. 1 byte = 8 bits; 1 KB = 1024 bytes; 1 MB = 1024 KB; 1 GB = 1024 MB; 1 TB = 1024 GB.
- The CPU contains the ALU, control unit and registers; its speed is measured in GHz.
Shortcuts and file types
- Ctrl+S save, Ctrl+P print, Ctrl+Z undo, Ctrl+Y redo, Ctrl+F find, Ctrl+A select all, Alt+F4 close window, F2 rename, Ctrl+Shift+N new folder.
- Extensions: .docx Word, .xlsx Excel, .pptx PowerPoint, .pdf portable document, .jpg image, .exe executable.
Worked example
A spreadsheet holds readings in A2 to A6 and you need the mean in A7. Click A7, type =AVERAGE(A2:A6) and press Enter. The colon means 'A2 through A6', while a comma lists separate cells, so =AVERAGE(A2,A6) would average only two values. Verify by adding the five readings and dividing by five.
Traps
Using 1000 instead of 1024 for memory units; treating Save and Save As as identical; assuming a deleted file leaves the Recycle Bin; opening links or attachments in unsolicited email.