G4G0-1/Semester 1/Computer Systems Internals & Linux/Week 2/Week 2 Computer Systems Internals & Linux.md

Lecture 1 (12:00)

Addition

Binary Base	2^7	2^6	2^5	2^4	2^3	2^2	2^1	2^0
Decimal	128	64	32	16	8	4	2	1
Int1	0	0	0	1	0	1	0	1
Int2	0	0	0	0	0	1	0	1
Overflow					1		1
Result	0	0	0	1	1	0	1	0
Decimal	26

Multiplication

Binary Base	2^7	2^6	2^5	2^4	2^3	2^2	2^1	2^0
Decimal	128	64	32	16	8	4	2	1
Int1	0	0	0	0	0	0	1	1
Factor							1
Result	0	0	0	0	0	1	1	0
Decimal	6

• Multiply binary shift to the left. Example is x2
• Multiplying by non powers of 2, split and multiply.

Binary Base	2^7	2^6	2^5	2^4	2^3	2^2	2^1	2^0
Decimal	128	64	32	16	8	4	2	1
Int1	0	0	0	1	0	0	1	1
Factor Decimal	6
Result 1	0	1	0	0	1	1	0	0
Result 2	0	0	1	0	0	1	1	0
Overflow				1	1
Total	0	1	1	1	0	0	1	0
Denary	114

• Example of 19x6, which simplifies into (19x4) + (19x2), which is shown above by doing two binary shifts and adding them together.

Workshop 1 (11:00)

CSV Manipulation

1. How many users are in the file?
2. Use a combination of head and tail to find the 5th line of the file
3. how many users use /bin/sh as their shell and how many use /bin/bash