CompSci Unit 1 Review by Harrison Cohn https://padlet.com/harrison_cohn/neqp43tztxl1 Without this study guide you will want to ! your head against a table. en-us 2016-10-25 14:36:33 UTC 2025-09-26 14:13:54 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Growing.png arath_luna https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133026769 2016-10-25 14:42:30 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133026769 harrison_cohn https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133027688 2016-10-25 14:44:56 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133027688 aliya_swanger https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133027927 2016-10-25 14:45:27 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133027927 Topics to cover ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133028537 * Number systems and conversions (binary, octo, hex etc)
* Representing data, text and colors.
* Digital vs. analogue signals

* System planning (presentations below )
* System design (discussion topics - review social and ethical issues)

* Pseudocode
* Flowcharts
* Trace tables]]> 2016-10-25 14:47:00 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133028537 Number System: harrison_cohn https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133028906 1. Another name for a base-10 number system is a Decimal Number System
2. To make reading and writing large numbers easier we use positional notation

Orders for Conversion: USE BASE 2 WHEN CONVERTING
  • Decimal (base 10): Computer does not take in, have to convert it to hex, octal, or binary. 
  • Hex (base 16): Broken into blocks of 4 for converting
    • Goes 0-9, then A-F (aka 10-15)
  • Octal (base 8): Break binary into blocks of 3 for converting
    • Goes 0-7 for each bit
  • Binary (base 2): Broken into 2s
    • Ranges from 0-255 for one byte

Ladder Technique:
  • Used for converting decimals to binary
    • Take number, divide it by 2, put remainder on outside
    • In space above, but what the answer to the division problem was, and repeat until you reach 0
Positional Notation Technique:
  • Set up the 2^x line until one number reaches/passes the decimal, and then find out how you can combine them to reach that point


]]> 2016-10-25 14:47:52 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133028906 Data Representation aliya_swanger https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133030315 All data in a computer is stored as BINARY BITS

ANALOG: continuous data
A CLOCK >directly proportional to the world and in continuous

DIGITAL: either on or off, easy for a computer to understand (even when interrupted by sound
MOST ELECTRONIC DEVICES>a phone or computer

We use binary in computers because it is either on or it's off, making it easy for the computer to read.
Furthermore, electronic signals are easier to maintain if they transfer only binary numbers.
  ]]> 2016-10-25 14:51:29 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133030315 Numeric Data aliya_swanger https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133030520 BIT: a single binary digit

BYTE: 8 bits

2'S COMPLIMENT: used by most computers to represent negative numbers. The largest (positive) integer you can write in 2's compliment is 127, the smallest (negative) integer you can write is -128
REMEMBER that 0 is included as a positive integer, that's why 127 is the largest number.

HOW DO I 2'S COMPLIMENT???
this example will show how to convert -10 into 2's compliment
1) WRITE THE POSITIVE VERSION OF YOUR NUMBER IN BINARY
10 = 00001010

2) FLIP ALL OF THE DIGITS (1s become 0s)
flip = 11110101

3) ADD 1 TO YOUR NEW NUMBER
11110101 + 1 = 11110110
NOTE: when you add 1 + 1 you get 2, in binary that is 10, so when you add 1 to the flipped number whose last number is already 1, you would get 10, meaning you have to carry the one onto the next digit!!!!!

4) YOU HAVE YOUR NEW NUMBER
-10 = 11110110 

5) NOTE: REMEMBER your left most digit is your sign digit, NOT A REPRESENTATIVE NUMBER DIGIT (1 is negative, 0 is positive)

6) NOTE: REMEMBER that when converting from a 2's compliment negative number to a positive number, subtract one from the right most digit

]]> 2016-10-25 14:51:54 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133030520 Flowcharts arath_luna https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133034499 Rectangles - Sequential operations
Parallelagrams - Output/Input
Diamonds (Rhombus) - Decisions (if, for, while, do while)]]> 2016-10-25 15:00:37 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133034499 Psuedocode arath_luna https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133036073  A description of a computer programming algorithm that uses the structural conventions of programming languages but omits language-specific syntax.

Variables are written in uppercase (RED = 0)
Keywords are written in lowercase (loop, while, etc)
Values are are set using equal signs "=" (RED = 7, SUM = 2)
Print to screen is given by the term "output" (output RED, output "blue")]]> 2016-10-25 15:03:42 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133036073 Trace Tables arath_luna https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133042563 A technique used to test algorithms in order to verify that no logical errors occur while an algorithm is being processed. Trace tables are typically used when loops and/or arrays are introduced in an algorithm]]> 2016-10-25 15:17:00 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133042563 Text Representation aliya_swanger https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133045121 ASCII: American Standard Code for Information Interchange, based off of the english alphabet, gives you decimal and hex codes for different characters on the american keyboard (lower-case letters, capital letters, backslash, !)

HOW DO I USE ASCII???

FOR THIS EXAMPLE WE WILL USE THE LETTER "b"

1) find the hex code for your character
b = 62

2) convert each digit in the code into binary
hex code 6 = 0110
hex code 2 = 0010

3) combine the binary numbers
62= 01100010

YOU CAN ALSO WORK THIS BACKWARDS TO CONVERT BINARY INTO HEX AND THEN USE YOUR CHART TO FIND THE CHARACTER. REMEMBER TO SPLIT THE BINARY NUMBERS INTO GROUPS OF 4

UNICODE: a chart for all of the other characters not in the english language, the first 256 characters are the same as the ones in ASCII (Chinese characters, scientific numbers)]]> 2016-10-25 15:21:48 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133045121 Practice exam questions  ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133585298 2016-10-27 12:24:17 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133585298 chloe_parsons https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133633859 2016-10-27 14:25:33 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133633859 Exam Questions ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133635030 2016-10-27 14:28:07 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133635030 Q1 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133636377 The cache memory improves the performance of a CPU by storing needed data closer to where it’s needed. By increasing the size of the cache memory, the computer will be able to perform faster, as there is more information that can be quickly be reached when needed. ]]> 2016-10-27 14:31:09 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133636377 Q2 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637111 By using a prototyping approach when designing a new computer system, programmers can gain much valuable insight. One major advantage of this technique is that they (the programmers) are able to see how individuals interact with and react to their product, allowing them to make changes before the final release (so that the final product is near perfection).]]> 2016-10-27 14:32:44 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637111 Q3 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637452 a) 00001111= 15. Therefor 11110001 = -15
b) 127 = 01111111

]]> 2016-10-27 14:33:32 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637452 Q4 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637674 a) = BD
b) = 10101001
]]> 2016-10-27 14:34:04 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637674 Q5 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637773 This code, once executed, will define V as 2.5. 
This is due to the fact it defines it as z/y, with z equaling x (which is equal to 15) and y equaling 6. Since v is a double, not an integer, the answer can be a decimal, which it is.]]> 2016-10-27 14:34:18 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637773 Q6 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637808 1111101001110001]]> 2016-10-27 14:34:24 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637808 Q7 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637840 2016-10-27 14:34:27 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637840 Q8 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637888 a) 33 = 00100001 -33 = 11011111
b) -128 t0 127

]]> 2016-10-27 14:34:32 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637888 Q7 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637924 7a.
Students could possibly download viruses or malware from unsafe sites on the internet, which has the possibility of compromising the school’s data. 

7b.
In order to prevent this, school’s have a few options to monitor student’s use of the internet:
- administrator passwords can be required for downloads from the internet, to hopefully prevent students from downloading any malware 
- administrators can keep tabs on students’ internet history 
- administrators can block websites that seem unsafe ]]> 2016-10-27 14:34:36 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133637924 Q9 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133638385 The ALU is the part of the computer which does equations that involve binary and integer equations.]]> 2016-10-27 14:35:31 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133638385 Q10 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133638963  ]]> 2016-10-27 14:37:07 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133638963 Q11 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642334 A). A feasibility report created for putting in new systems should include several details, such as the cost of implementing the new system and compatibility with existing software.
B). Several different factors will impact the companies decision in using commercial software or customized software. First, they will consider the price, as they want it to fit in their budget, with commercial software usually being the most cost effective option. Second, they will want the software to be compatible with existing software (as they do not want to lose data), something easier to find in customized software. Finally, security will play a large role as large companies value protecting their data, usually drawing them towards commercial software as they have more more experience and defenses in place. 
C). More than one cycle of analysis and design would most likely benefit the quality of the system, and the companies overall content with it. First, by going through several designs, the company will be able to pick out specifically what they want in their system, meaning they do not need to edit it. Second, by having multiple designs set up, in the event one was compromised, there would be an easier backup plan. Additionally, by analyzing it several times, the company can encounter aspects and errors in the system that they may have missed when going through it the first time, again benefiting them in the long run.]]> 2016-10-27 14:46:22 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642334 Q12 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642392 12a.
SaaS is a software delivery model which allows a server to be accessed by users through the internet.

Examples would be: Facebook, google docs, Netflix, and pretty much any email client. 

Features include: easier administration, automatic updates and patch management, compatibility (all users will have the same version of the software), and global accessibility. 

12b.
In regards to security, there are many concerns when it comes to SaaS. Being based on the internet, it could be much easier to be hacked into. Users of these softwares could have sensitive information stored in them. ]]> 2016-10-27 14:46:30 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642392 Q13 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642432 a)
i) "discount is 10%"
ii) "discount is 5%"
iii) "discount is 2%" "discount is 10%"

b) The second strand should be an else if statement instead of an if statement. Because of this error certain inputs will have 2 outputs, as each input goes through 2 different loops.]]> 2016-10-27 14:46:37 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642432 Q14 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642481 Today's society revolves around technology, and being connected to the rest of the world 24/7. Nowadays we are more connected than ever, and we are able to share information in an instant, including research, current events, etc. On the other hand, this also allows for the easy spread of misinformation, leading to false rumors and misinterpretation of actual, or fake, facts.]]> 2016-10-27 14:46:45 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642481 Q15 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642523 a)
i) interviews are more personal and have a wider  variety of possible questions and answers
ii) questionnaires are more efficient and can reach a wider audience 

b) One solution could be more expensive and the other cheaper

c) 
Testing
--Test that the new computer system will work with the server and for the company
Data migration
--Transfer all of the old (backed up) data from the old system to the new one

]]> 2016-10-27 14:46:52 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642523 Q16 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642558 2016-10-27 14:46:58 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642558 Q17 ed_downes https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642591 2016-10-27 14:47:05 UTC https://padlet.com/harrison_cohn/neqp43tztxl1/wish/133642591