The random number generator

Seeding:

The random number generator is seeded with time in seconds since some unknown epoch modulo 65536.

Iteration

The random number state is iterated by:
X' = (22695477 * X + 1) mod 2^32
This formula is invertible:
X = (690295837 * (X' - 1) ) mod 2^32
The RNG has a single cycle of 2^32 numbers.

Random numbers

To generate a random number, the RNG is iterated once, then the RNG state is taken, divided by 65536 and ANDed with 32767.
Typically the resulting number is then divded by something depending on what the random number is used for and taking the remainder, e.g.:

RNG usage:

 * Number of enemies doesn't seem to matter
 

Fades

Each time character transitions between rooms, a dialog box appears or disappears there is a fade.
This fade is random, and the fades vary wildly in length, so this is a good subject for luck manipulation.
Most fades are very slow.
The fade type is determined by taking a random number, dividing 11 and taking the remainder:
RemainderFade typeNotes
0Whole screen randomFast, uses random numbers
1From top and bottom to center
2Random from topUses random numbers
3Striped from top and bottom
4From center to top and bottom
5From left and right to center
6From center to left and rightCan be canceled
7Random from bottomUses random numbers
8Random from leftUses random numbers
9Random from rightUses random numbers
10Diagonal
The fade type 6 is special: It can be canceled by a keypress. No other fade type behaves that way.
The fade type 0 is greatly faster than others (except canceled type 6).

The missing three keys

The missing three keys are in following places:
 * The security has to be deactivated first, otherwise it will blow up.

Tricks

Jump trick

This only works when moving left for some reason.
Hit either roll or jump when running. The character speed increases to 12 for one frame (normal running is 8).

Event invincibility

Phones with optional stuff:

Noid removers

Using noid remover will:

Memory addresses

The addresses can change, here are addresses from one playthrough
Even if these addresses change, the differences between addresses should remain constant.
0x1E344WordCharacter X position
0x1E3B4WordTime left minutes
0x1E3BAWordTime left seconds
0x1E3BEWordTime left quater seconds
0x1DE34DwordRNG state
0x1707CWordSecurity code (0-999)

GameResources/DOS/AvoidTheNoid last edited by Ilari on 4/1/2012 10:39 AM
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