IT Questions and Answers :)

Friday, April 26, 2019

In Windows, how do you enter ASCII characters that are not displayed on a keyboard?

In Windows, how do you enter ASCII characters that are not displayed on a keyboard?

Ctrl-Alt + keyboard keys corresponding to ASCII
Alt + ASCII decimal value on number pad
Shift-Alt + keyboard keys cooresponding to ASCII
Alt + ASCII decimal value using keyboard top 

 

EXPLANATION

I have used Alt + ASCI decimal value entered on the number pad for many years for various reasons.  It's a nice way to hide characters in passwords or files you want to keep secure. A password with an Alt-255 (null) character will display as a space and baffle even the most experienced hacker. While working in a public school system, my remote software client was VNC and it stored the password in hexidecimal format in the registry which above average students might
possibly be able to decode. But when ASCII 255 characters are found, they're totally confused. I have also named programs and batch files with just the null character plus extension to make it hidden.  I have also used ASCII extended box and line characters to make things look nicer in batch programs, but is limited with newer versions of Windows that lack ANSI.sys not being standard (it can be enabled).

SOURCE

https://support.office.com/en-us/article/insert-ascii-or-unicode-latin-based-symbols-and-characters-d13f58d3-7bcb-44a7-a4d5-972ee12e50e0
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Wednesday, April 10, 2019

What encoding scheme represents text in computers and communications equipment?

What encoding scheme represents text in computers and communications equipment?

  • Hexadecimal
  • UEFI
  • Binary
  • ASCII

What encoding scheme represents text in computers and communications equipment?

EXPLANATION

ASCII, abbreviated from American Standard Code for Information Interchange, is a character-encoding scheme (the IANA prefers the name US-ASCII). ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern
character-encoding schemes are based on ASCII, though they support many additional characters.

SOURCE

https://en.wikipedia.org/wiki/ASCII
 
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Monday, February 25, 2019

The hexadecimal 7F3E converted to binary is?

The hexadecimal 7F3E converted to binary is?

  • 0111 1111 1100 1110
  • 1000 1111 0011 1110
  • 0111 1111 0011 1101
  • 0111 1111 0011 1110 
 
The hexadecimal 7F3E converted to binary is?

EXPLANATION

7 = 0111
F = 1111
3 = 0011
E = 1110
 
DecimalBinaryHexadecimal
000000
100011
200102
300113
401004
501015
601106
701117
810008
910019
101010A
111011B
121100C
131101D
141110E
151111F

160001 000010
170001 000111
180001 001012
190001 001113
200001 010014
210001 010115
220001 011016
230001 011117
240001 100018
250001 100119
260001 10101A
270001 10111B
280001 11001C
290001 11011D
300001 11101E
310001 11111F
320010 000020
330010 000121
340010 001022
350010 001123
360010 010024
370010 010125
380010 011026
390010 011127
400010 100028
410010 100129
420010 10102A
430010 10112B
440010 11002C
450010 11012D
460010 11102E
470010 11112F
480011 000030
490011 000131
500011 001032
510011 001133
520011 010034
530011 010135
540011 011036
550011 011137
560011 100038
570011 100139
580011 10103A
590011 10113B
600011 11003C
610011 11013D
620011 11103E
630011 11113F
640100 000040
650100 000141
660100 001042
670100 001143
680100 010044
690100 010145
700100 011046
710100 011147
720100 100048
730100 100149
740100 10104A
750100 10114B
760100 11004C
770100 11014D
780100 11104E
790100 11114F
800101 000050
810101 000151
820101 001052
830101 001153
840101 010054
850101 010155
860101 011056
870101 011157
880101 100058
890101 100159
900101 10105A
910101 10115B
920101 11005C
930101 11015D
940101 11105E
950101 11115F
960110 000060
970110 000161
980110 001062
990110 001163
1000110 010064
1010110 010165
1020110 011066
1030110 011167
1040110 100068
1050110 100169
1060110 10106A
1070110 10116B
1080110 11006C
1090110 11016D
1100110 11106E
1110110 11116F
1120111 000070
1130111 000171
1140111 001072
1150111 001173
1160111 010074
1170111 010175
1180111 011076
1190111 011177
1200111 100078
1210111 100179
1220111 10107A
1230111 10117B
1240111 11007C
1250111 11017D
1260111 11107E
1270111 11117F
1281000 000080
1291000 000181
1301000 001082
1311000 001183
1321000 010084
1331000 010185
1341000 011086
1351000 011187
1361000 100088
1371000 100189
1381000 10108A
1391000 10118B
1401000 11008C
1411000 11018D
1421000 11108E
1431000 11118F
1441001 000090
1451001 000191
1461001 001092
1471001 001193
1481001 010094
1491001 010195
1501001 011096
1511001 011197
1521001 100098
1531001 100199
1541001 10109A
1551001 10119B
1561001 11009C
1571001 11019D
1581001 11109E
1591001 11119F
1601010 0000A0
1611010 0001A1
1621010 0010A2
1631010 0011A3
1641010 0100A4
1651010 0101A5
1661010 0110A6
1671010 0111A7
1681010 1000A8
1691010 1001A9
1701010 1010AA
1711010 1011AB
1721010 1100AC
1731010 1101AD
1741010 1110AE
1751010 1111AF
1761011 0000B0
1771011 0001B1
1781011 0010B2
1791011 0011B3
1801011 0100B4
1811011 0101B5
1821011 0110B6
1831011 0111B7
1841011 1000B8
1851011 1001B9
1861011 1010BA
1871011 1011BB
1881011 1100BC
1891011 1101BD
1901011 1110BE
1911011 1111BF
1921100 0000C0
1931100 0001C1
1941100 0010C2
1951100 0011C3
1961100 0100C4
1971100 0101C5
1981100 0110C6
1991100 0111C7
2001100 1000C8
2011100 1001C9
2021100 1010CA
2031100 1011CB
2041100 1100CC
2051100 1101CD
2061100 1110CE
2071100 1111CF
2081101 0000D0
2091101 0001D1
2101101 0010D2
2111101 0011D3
2121101 0100D4
2131101 0101D5
2141101 0110D6
2151101 0111D7
2161101 1000D8
2171101 1001D9
2181101 1010DA
2191101 1011DB
2201101 1100DC
2211101 1101DD
2221101 1110DE
2231101 1111DF
2241110 0000E0
2251110 0001E1
2261110 0010E2
2271110 0011E3
2281110 0100E4
2291110 0101E5
2301110 0110E6
2311110 0111E7
2321110 1000E8
2331110 1001E9
2341110 1010EA
2351110 1011EB
2361110 1100EC
2371110 1101ED
2381110 1110EE
2391110 1111EF
2401111 0000F0
2411111 0001F1
2421111 0010F2
2431111 0011F3
2441111 0100F4
2451111 0101F5
2461111 0110F6
2471111 0111F7
2481111 1000F8
2491111 1001F9
2501111 1010FA
2511111 1011FB
2521111 1100FC
2531111 1101FD
2541111 1110FE
2551111 1111FF
 
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Thursday, February 14, 2019

Which name below is not usually another name for "nibble" in computing & networking?

Which name below is not usually another name for "nibble" in computing & networking?

  • tetrad
  • quartet
  • quadbit
  • quaddigit 

Which name below is not usually another name for "nibble" in computing & networking?

EXPLANATION

A "nibble" contains 4 digits, as opposed to a "bit" containing 1 digit or a "byte" containing 8 digits. All of the above except "quaddigit" references or are other names for nibble. The most
common reference to quad-digit in technology are 4 position timers, like an oven displaying the time or countdown timer.

SOURCE

https://en.wikipedia.org/wiki/Nibble
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Thursday, October 25, 2018

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

  • Cross-site scripting
  • Fuzzing
  • Cross-site request forgery
  • Input validation 

You can use which of the following to inject massive amounts of random data into a program or protocol stack for bug detection?

EXPLANATION

You can use fuzzing to inject semi-random data into a program or protocol stack in order to detect bugs.

Fuzz testing or Fuzzing is a Black Box software testing technique, which basically consists in finding implementation bugs using malformed/semi-malformed data injection in an automated fashion.

Fuzz testing was developed at the University of Wisconsin Madison in 1989 by Professor Barton Miller and his students. Their (continued) work can be found at http://www.cs.wisc.edu/~bart/fuzz/ ; it's mainly oriented towards command-line and UI fuzzing, and shows that modern operating systems are vulnerable to even simple fuzzing.


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Tuesday, September 25, 2018

Which of the following is NOT a computer programming language?

Which of the following is NOT a computer programming language?

  • Lisp
  • Occam
  • SNOBOL
  • Modal

EXPLANATION

MODAL isn't a programming language but is used in computer applications, especially within websites. It is a graphical window control element, subordinate to an application's main window.
SNOBOL (StriNg Oriented and symBOlic Language), is a text-string-oriented language developed by AT&T Bell Labs in the 1960s.
LISP, developed in the 1950s, is one of the oldest high-level programming languages and is only pre-dated by the likes of FORTRAN.
OCCAM was one of the earliest Concurrent programming languages, developed by INMOS as the native programming language for their Transputer Microprocessors.

SOURCE

https://en.wikipedia.org/wiki/List_of_programming_languages
 
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Tuesday, September 4, 2018

In Unix systems, what are semaphores?

In Unix systems, what are semaphores?

  • A technique for pipeline deletion inside processes
  • A technique for coordinating or synchronizing activities
  • A technique for pipeline creation inside threads
  • A technique for Traffic lights management inside an operating system 

 
In Unix systems, what are semaphores?

EXPLANATION

In programming, especially in Unix systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources.
A semaphore is a value in a designated place in operating system (or kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.
Semaphores are commonly use for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or "functions" for managing semaphores.

SOURCE

https://whatis.techtarget.com/definition/semaphore
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