(C) Research / Volgasoft
Scientific RND
In my esteemed journal Spectrum
Expert were laid out at least all the materials for self-writing
wire, and even the cast wire
engine ELITE. Now we learn how to generate pseudo-random
numbers, and thus learn to write everything that happens inside
the station (map of the galaxy and the names of the planets for
example:). Enough will scrape a modest materialchik on
likeness of artificial intelligence, and anyone can write the
elite for two months:
Main methods of generating random
There are two numbers (and finally can - one):
1) the shift of floating point numbers
(Sometimes with the admixture of shifted copies);
2) Papal method:) Tyk Now, consider the Pope's method:
N [i +1] = mod (A * N [i], Z); - where mod = Modulo
In other words: the next number = remainder of division of some
constants A, multiplied by the previous number and the constant
Z. That's it!
On the finger assembly:
constA EQU 137
; Z EQU 8
N EQU 3; seed
LD IX, array; array address
LD (IX), N
LD DE, constA; constant A
LD B, 32; how many numbers to generate
LL1
LD L, (IX)
LD H, 0
PUSH DE
CALL MUL_HL_DE; "A * N [i]"
POP DE
LD (IX +1), L; remainder of the division by 256, also
known as the low byte
INC IX
DJNZ LL1
; Ready
The range of values generated numbers
depends on the constants. In the example, Z = 256,
A = 137. The values of Z - choose to taste
(Actually, in this example would not hurt
beginning to shift the result of multiplying
right by one bit, and then take the remainder). The values of
A are chosen so that the distribution was close to uniform.
Usually taken number (I forgot how their school was
named - which are divided into themselves and one) such as 5,
7.13, 17, 19, 23, etc. Make sure that there was no zeros,
otherwise the generator will rise. As I have said that numbers
were obtained not only odd or even - to play with the
translations.
To generate numbers not only
arranged in a specified number of bits (8 -
1 .. 255, 7 - 1 .. 127) will have to ruin a few numbers, or use
multiple generators, for example the numbers 1 .. 191:
LD A, n1
AND A, 1963
LD C, A
LD A, n2
AND A, 127
ADD A, C
LD (RESULT), A
But how to generate the names of the planets in the elite
- everyone knows - we take, we make an array of syllables (two
letters) and we start the generator - one number corresponds to
one syllable, and rolls the two-letter planet, four, six:
By the way, like algorithm is used in calculating the
checksum, the including at the same VG93.
Well that's all: How to tell you about the current
AI (or someone will tell in the pages
Adventurer 'a) from you with each of the elite
:))).
