RIP #01 23 ноября 1997

Программирование

School Hacker - Cycle BASE -1 ": Horner's scheme, Radix.

    As testified to polls conducted by the newspaper Move,
One of the most desired columns by the readers was
Category dedicated to non-traditional ways of programming and
hacking in general. We hope that the cycle Hekerskaya school 
"you interested. However, immediately warned that the full 
version of edition no. And so, if you wish to continue

publication, please contact us and we will try to
Based on your letters to beg the author ...



        Hekerskaya School. Cycle "BASE". Version B7.4.11



    All rights training materials Hekerskoy Schools
belong Arvi Hacker (Ilya Vasilyev), Moscow,
2:5020 / 287 @ fidonet, arvi@hsys.msk.ru, 
ath@verte.dnntm.rssi.ru. If you use any part of this material 
for any purpose obligatory link to the source. In the case of 
commercial use or for teaching more than one

Rights required a preliminary agreement with the author.
This material was originally intended for students and
students, pupils Hekerskoy School.


    For the first time published the full text hekerskoy BASE. 
This version, in Russian, is intended for publication in

ehokonferentsii FIDO RU.HACKER. Thus, the text used
some slang, signs of emotion and the allocation adopted in the 
network. 

>>>


    So marks the spot intended for the already trained
people. Usually these people know one or several languages
programming. In this scenario, the "base" as the main
language chosen BASIC. Solely because it is available at
a wider range of desktops than any other language. In most
cheap computers, which are now available for free on the dig
any garbage (ZX Spectrum, BK-0010), he even sewn into the ROM. 
Also it can be found at any supply DOS'a. There he is called

BASICA, GWBASIC or QBASIC.


    In any case, the hacker needs to know all languages
programming, and with the start of their study, so it
important?

>>>


    Signs of coolness can be invested.

<<<
<<<


    Each base, and there are only three, is divided into two 
seminars. For domestic students who are ready to fully dedicate 
himself hekerstvu, BASE read one day, one week apart. For

mainstream-one workshop per day, two seminars a week. In
both of these modes before and after the lesson (with severe 
exercise) CASE 5-minute meditation. Hacker learned to enter the

a state of heightened activity in the brain-hack mode.


    When people are not important to the learning curve can be 
studied one by one theme day. Special training of the brain 
that does not give only knowledge transfer. With distance 
learning you must choose the his rhythm.



             A small part of the series "Introduction"

             ===================================


    My school is built as a school of martial arts new age
Computer martial arts. The role of Japanese in Karate
hekerstve does English. Therefore, when a new term
will immediately be given to its English equivalent.


    I believe that the hacker - primarily the state of 
consciousness. Therefore, its main task put to the development 
of research approach to life, ability to learn

large amount of information in a short time, grokinga
(Grocking)-vision response.


    Although the cycle is attached Hekerskaya Ethics (The 
Hackers Ethic), in a series of Baseline and follow not 
considered moral and ethical aspects hekerstva, only the 
technical side. These aspects, as well as more traditionally 
passed on from teacher (guru) to student. Therefore, the 
personal contact is necessary for the / true / / transmission / 
Art. 


    Also in hekerstve nothing about those who are afraid of the 
word FUCK on the terminal screen, bottles of beer / vodka and 
smoke marijuana. I myself do not use drugs, cigarettes and 
alcohol, I grates from abusive speech. And most readily take 
students with similar beliefs.



    But it so happened that at the moment hekerstvo, existing
semi-legal and growing only at the bottom of our society, leads
to the emergence of viruses / trojans with foul and filled
slogans addicts. Beer and vodka are the international
currency. In the most prestigious institutes of smoking "weed" 
on stairwells and halls of residence.



    If you do not just pure art, but also
applied aspects - disassemble the virus, track
attacks, sooner or later you will be faced with
all this mud. : ("Underground is underground" (C) Umka.


    I myself prefer, and drink tea with the students - a drink 
of Zen. 



                             BASE-1


                  The first seminar. Base.



                      B1: 1 Horner scheme.

                      ===================

>>>


    The amount of type 5x ^ 2 +12 x +4 is called a polynomial 
(or polinomomzapomnite that word) of one variable. (By ~ I mean 
exponentiation. This notation is taken from BASIC.) Scheme 
Horner for the calculation of the polynomial is of the 
following: 

12x ^ 4 +56 x ^ 3 +3 x ^ 2 + x +45 = (((12x +56) x +3) x +1) x 
+45 34x ^ 4 +3 x ^ 2 = (((34x +0) x +3) x +0) x +0 = (34x ^ 2 
+3) x ^ 2 

At BASIC'e:

P = A (N): FOR I = N-1 TO 0 STEP -1: P = P * X + A (I): NEXT

Meditate.

<<<


                     B1: 2 Number systems

                     ======================


    In most countries, despite the different languages, say
on an identical, "in Arabic, using ten digits (digit),
0123456789. When it comes to the last digit, use
two-digit number (number). If we had only five digits,
01234, we would have thought so: 0 1 2 3 4 10 11 12 13 14 20 21 
22 23 24 30 31 32 33 34 40 41 42 43 44 100 101 102 103 104 110 
111 112 ...



    The usual number system is called the decimal (decimal,
abbreviated dec). The one we just discussed -
quinary. Number system in English - number system.
Number of digits in radix - the radix
(Base, sometimes radix).


    At the base of more than a decade we have to introduce new
figures. As they decided to use the letters
(Alpha). Thus, in semnadtsaterichnoy number system we would 
have thought 0 1 2 3 4 5 6 7 8 9 ABCDEFG 10 11 12 13 14 15 16 
17 18 19 1A 1B 1C 1D 1E 1F 1G 20 .. GD GE GF GG 100 101 102 .. 
When sufficiently large basis (for what?), this will not work.



    Different number systems - as many languages. One and
the same number may be quite different records in different
number systems. Thus, the number 127 in decimal is equal to 7F
hexadecimal and binary 1111111. Just as the words
translate from one language to another, the numbers can be 
transferred from one number system to another. These number 
systems-something like a computer language for numbers. Binary 
(binary, abbreviated bin) number system is used on virtually

all machines. In addition to her on the machines PDP-11, 
BK-0010, DCK using octal (octal, short

oct). On machines IBM PC, Macintosh, VAX instead octal
use a hex (hexadecimal, abbreviated hex)
number system.


    Of course, the zeros before the number does not change the 
value of any which of the number systems. Very well, if you will

imagine that in front of each number as it is written
infinite number of zeros is your solution at the beginning
second base (B2: 1).


    I strongly advise to find a little bit in different systems
notation. If you take a piece of paper in the box and 
pronumeruete line first in the decimal system, then in

octal, hexadecimal and binary, you get a good
plate transfer the first thirty with a small number between
most used in hekerstve number systems. Write
this table also the numerical values ​​of all the Latin 
letters, you this is very useful in the future.



    Translation table of the first 16 numbers between binary, 
decimal and hexadecimal number systems in our school called the

table of the Dragon (B1: 5).

>>>


    A specific pattern of digits is not important. The fact 
that zero is denoted circle, and the unit-stick, just a 
historical conventionality. We may normally be considered in 
the ternary system reckoning with numbers% $ ^: $% ^ $% $ $% ^ 
^ ^ ^ ^ $ $%% $% $ $% ^ $ $% $ $ $ $ $ ^ $ ^% $ ^ $ $ ^ ^%%... 
A number system, where instead of numbers Russian letters are 
used, is very promising in the computer world-because of 
Russian letters (not counting the letter E with two points) 
only 32, but it's a power of two! 


    Likewise, you should not take seriously the requirements of
use the letters after the nines. ASCII-characters
standing after the nines, for example, no worse. Is that
fewer people will understand you. (I do not recommend this cover
my laziness to do the normal output of 16 hexadecimal numbers. 
Confused when analyzing the output.)



    According to the present to indicate the number system must 
be specified not its foundation, and a vector (an ordered 
array) of numbers. Assuming in number systems with a vector 
basis in which the figures are "Out of order" (eg, octal with a 
vector 31276504), one can significantly hamper the 
understanding of what is happening. 


    At a seminar in our school, "Hacking toys without debugger" 
I talked about hacking the game cartridge for Ecco the Dolphin

set-top box SEGA. This game was the quest
dolphin journey on the seas, oceans, in search of his
missing family. In order not to die, the dolphin had from time 
to time to surface and breathe oxygen.



    This game was a system of password save - the beginning of 
each Phase issued its code by entering you can immediately get

at that stage. In the analysis of these codes (they consisted 
of six Latin letters) was that they represent a number of

dvadtsatishestirichnoy system, with the vector base
ABCDEFGHIJKLMNOPQRSTUVWXYZ - all in Latin characters for
alphabetically. In this notation, for example, the decimal 
number 10 will be written as K. A number of FUCK, translated 
from this decimal system, will appear as 101462. (Proverte.)



    Translating the number of such 26-hexadecimal-binary system
and finding the type of checksum, I learned not only to move
at the level of play, on which I want, but on and off
oxygen demand. There was and bitik responsible for
it.

<<<


    In mathematics, taken to indicate the radix
(With the numbers 012 ... 9ABCD ... Z) at the bottom-right of 
the numbers. At the same time base is written in the decimal 
system. We, in text files, the "base", it will be marked as 
follows: 1FC_16 denotes 1FC in hexadecimal.



    Note (check on your table) that 10 .. 0_x = x ^ n, where
n - the number of zeros after the unit.


                                        (To be continued ...)