Matrix digital rain

From Rosetta Code
Task
Matrix digital rain
You are encouraged to solve this task according to the task description, using any language you may know.

Implement the Matrix Digital Rain visual effect from the movie "The Matrix" as described in Wikipedia.

Provided is a reference implementation in Common Lisp to be run in a terminal.

Ada

Should work with ANSI terminals.

with Ada.Text_IO;
with Ada.Numerics.Discrete_Random;
with Ada.Strings.Fixed;

procedure Digital_Rain is
   type Column_Type     is range 0 .. 150;
   type Row_Type        is range 0 .. 25;
   type Character_Range is new Character range 'A' .. 'Z';
   subtype Delay_Range  is Integer range 2 .. 6;

   package Column_Random    is new Ada.Numerics.Discrete_Random (Column_Type);
   package Row_Random       is new Ada.Numerics.Discrete_Random (Row_Type);
   package Character_Random is new Ada.Numerics.Discrete_Random (Character_Range);
   package Delay_Random     is new Ada.Numerics.Discrete_Random (Delay_Range);

   Column_Generator    : Column_Random.Generator;
   Row_Generator       : Row_Random.Generator;
   Character_Generator : Character_Random.Generator;
   Delay_Generator     : Delay_Random.Generator;

   Esc     : constant Character := Character'Val (8#33#);
   Running : Boolean   := True;
   Char    : Character;
   use Ada.Text_IO;

   protected Text_Out is
      procedure Put_At (Row : Row_Type; Col : Column_Type;
                        Color : Integer; Item : Character);
   end Text_Out;

   protected body Text_Out is
      procedure Put_At (Row : Row_Type; Col : Column_Type;
                        Color : Integer; Item : Character)
      is
         use Ada.Strings;
      begin
         Put (Esc & "[" &
                Fixed.Trim (Row'Image, Left) & ";" &
                Fixed.Trim (Col'Image, Left) & "H");             -- Place Cursor
         Put (Esc & "[" & Fixed.Trim (Color'Image, Left) & "m"); -- Foreground color
         Put (Item);
      end Put_At;
   end Text_Out;

   task type Rainer;

   task body Rainer is
      Row : Row_Type;
      Col : Column_Type;
      Del : Delay_Range;
   begin
      Outer_Loop:
      loop
         Col := Column_Random.Random (Column_Generator);
         Row := Row_Random.Random (Row_Generator);
         for Rain in reverse Boolean loop
            Del := Delay_Random.Random (Delay_Generator);
            for R in 0 .. Row loop
               if Rain then
                  if R in 1 .. Row then
                     Text_Out.Put_At (R - 1, Col, Color => 32, Item => Char);
                  end if;
                  Char := Character (Character_Random.Random (Character_Generator));
                  if R in 0 .. Row - 1 then
                     Text_Out.Put_At (R, Col, Color => 97, Item => Char);
                  end if;
               else
                  Text_Out.Put_At (R, Col, Color => 30, Item => ' ');
               end if;
               delay 0.020 * Del;
               exit Outer_Loop when not Running;
            end loop;
         end loop;
      end loop Outer_Loop;
   end Rainer;

   Dummy   : Character;
   Rainers : array (1 .. 50) of Rainer;
begin
   Put (ESC & "[?25l");        -- Hide the cursor
   Put (ESC & "[40m");         -- Black background
   Put (ESC & "[2J");          -- Clear Terminal

   Get_Immediate (Dummy);
   Running := False;
   delay 0.200;

   Put (ESC & "[?25h");        -- Restore the cursor
   Put (ESC & "[0;0H");        -- Place cursor
   Put (ESC & "[39m");         -- Default foreground
   Put (ESC & "[49m");         -- Default backgound
   Put (ESC & "[2J");          -- Clear Terminal
end Digital_Rain;

Amazing Hopper

Translation of: BASIC

VERSION 1:

#include <basico.h>

#proto desplegarmatrixrain(_X_,_Y_,_Z_,_W_)

algoritmo
    
    permitir interrupción
    
    dimensionar (80) matriz aleatoria entera ( -50, t )

    y=0

    color(232,232)
    borrar pantalla
    
    enfatizado
    
    iterar

        iterar para(i=1, #(i<=80), ++i )
            cuando ( #(t[i]>50) ){ #(t[i]=0) }
            #basic{ 
                 t[i] += 1
                 y = t[i]
                 desplegar matrix rain(232,232,i,(y-10))
                 desplegar matrix rain(22,232,i,(y-9))
                 desplegar matrix rain(22,232,i,(y-8))
                 desplegar matrix rain(22,232,i,(y-7))
                 desplegar matrix rain(28,232,i,(y-6))
                 desplegar matrix rain(28,232,i,(y-5))
                 desplegar matrix rain(34,232,i,(y-4))
                 desplegar matrix rain(34,232,i,(y-3))
                 desplegar matrix rain(40,232,i,(y-2))
                 desplegar matrix rain(46,232,i,(y-1))
                 desplegar matrix rain(232,40,i,y)
            }
        siguiente

        microsegundos(5000)
    hasta que una tecla sea presionada
    
    color(7,0)
    borrar pantalla
terminar

subrutinas

desplegar matrix rain(p,s,x,y)
    
    si ( y, está entre-excluyendo-(0,41) )
        color (p,s)
        imprimir en ( y,x, #(utf8(chr(33+((x*y) % 200)) )) )
    fin si

retornar
Output:
semejante a la imagen de la VERSION 2, pero con menos "cola"

VERSION 2:

#include <basico.h>

#proto desplegarmatrixrain(_X_,_Y_)

algoritmo
    
    dimensionar con (80) matriz aleatoria entera ( -50, t )
    matrices (ctexto, cfondo)
    '232,22,22,22,22,28,28,28,34,34,40,40,46,232' enlistar en 'ctexto'
    '232,232,232,232,232,232,232,232,232,232,232,232,232,40' enlistar en 'cfondo'

    color(232,232)
    borrar pantalla
    
    enfatizado
    
    iterar

        iterar para(i=1, #(i<=80), ++i )
            cuando ( #(t[i]>53) ){ #(t[i]=rand(-50)) }
            #basic{ 
                 t[i] += 1
                 desplegar matrix rain(i,t[i])
            }
        siguiente

        microsegundos(50000)

    hasta que una tecla sea presionada
    
    color(7,0)
    borrar pantalla
terminar

subrutinas

desplegar matrix rain(x,y)
    i=13, j=1
    iterar
        si ( #(y-i), está entre-excluyendo-(0,41) )
            color ( #(ctexto[j]), #(cfondo[j]) )
            imprimir en ( #(y-i),x, #(utf8(chr(33+((x*(y-i)) % 200)) )) )
        fin si
        --i, ++j
    mientras ' no es negativo(i)'
retornar
Output:

File:Matrix rain terminal linux 2.png

BASIC

FreeBASIC

Translation of: QBasic
Sub d(p As Ulong, s As Ulong, x As Long, y As Long)
    Color p, s
    If y > 0 And y < 24 Then Locate y, x: Print Chr(33 + (x * y) Mod 200);
End Sub

Dim As Long t(80)
For i As Integer = 1 To 80
    t(i) = Int(-50 * Rnd)
Next
Dim As Double s = Timer

Cls
Do
    For i As Integer = 1 To 80
        If t(i) > 28 Then t(i) = 0
        t(i) += 1
        Dim As Long y = t(i)
        d( 0, 0, i, y - 6)
        d( 2, 0, i, y - 5)
        d( 2, 0, i, y - 4)
        d(10, 0, i, y - 2)
        d(11, 0, i, y - 1)
        d( 0, 2, i, y)
    Next i
    
    Dim As Double l = Timer
    While l = Timer: Wend
Loop

QBasic

Original code programmed by nitro2k01

[1]
DECLARE SUB d (p!, s!, x!, y!)
DIM t(80)
FOR i = 1 TO 80
    t(i) = INT(-50 * RND)
NEXT
s = TIMER

CLS
WHILE 1
    FOR i = 1 TO 80
        IF t(i) > 28 THEN t(i) = 0
        t(i) = t(i) + 1
        y = t(i)
        d 0, 0, i, y - 6
        d 2, 0, i, y - 5
        d 2, 0, i, y - 4
        d 10, 0, i, y - 3
        d 10, 0, i, y - 2
        d 11, 0, i, y - 1
        d 0, 2, i, y
    NEXT

    l = TIMER
    WHILE l = TIMER
    WEND
WEND

SUB d (p, s, x, y)
    COLOR p, s
    IF y > 0 AND y < 24 THEN LOCATE y, x: PRINT CHR$(33 + (x * y) MOD 200);
END SUB

True BASIC

Translation of: QBasic
SUB d (p,s,x,y)
    SET COLOR p
    SET BACKGROUND COLOR s

    IF y > 0 AND y < 24 THEN
       SET CURSOR y, x
       PRINT CHR$(33+REMAINDER((x*y),200));
    END IF
END SUB

DIM t(80)
FOR i = 1 TO 80
    LET t(i) = INT(-50*RND)
NEXT i
LET s = TIME

CLEAR
DO
   FOR i = 1 TO 80
       IF t(i) > 28 THEN LET t(i) = 0
       LET t(i) = t(i)+1
       LET y = t(i)
       CALL d (0, 0, i, y-6)
       CALL d (2, 0, i, y-5)
       CALL d (2, 0, i, y-4)
       CALL d (10, 0, i, y-2)
       CALL d (11, 0, i, y-1)
       CALL d (0, 2, i, y)
   NEXT i
   LET l = TIME
   DO WHILE l = TIME
   LOOP
LOOP
END

Batch File

Works with: Windows 10

This code uses Windows 10 VT100 escape sequences.

:: Matrix Digital Rain Task from RosettaCode
:: Batch File Implementation

@echo off
setlocal enabledelayedexpansion

rem escape character (for Windows 10 VT100 escape sequences)
rem info: https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
for /f %%e in ('echo prompt $e^| cmd') do @set "esc=%%e"

rem set window size
set "col=120"   %== please don't make this too large ==%
set "row=30"   %== please don't make this too large ==%
mode con cols=%col% lines=%row%

rem set up the variables for display
set "rain_length=12"
for /l %%y in (1,1,%col%) do set "disp_col[%%y]= "   %== what to display ==%
for /l %%y in (1,1,%col%) do set "ctr_col[%%y]=0"   %== counter for rain length ==%

rem hide the cursor, and clear the screen
<nul set /p "=%esc%[?25l"
cls

:matrix_loop
for /l %%y in (1,1,%col%) do (
    if !ctr_col[%%y]! equ 0 (
        set "disp_col[%%y]= "
    ) else (
        set /a "rnd_digit=!random! %% 10"
        if !ctr_col[%%y]! equ 1 (
            set "disp_col[%%y]=%esc%[97m!rnd_digit!%esc%[32m"
        ) else if !ctr_col[%%y]! equ 2 (
            set "disp_col[%%y]=%esc%[92m!rnd_digit!%esc%[32m"
        ) else (
            set "disp_col[%%y]=!rnd_digit!"
        )
        set /a "ctr_col[%%y]=(!ctr_col[%%y]! + 1) %% (%rain_length% + 1)"
    )
    rem drop rain randomly
    set /a "rnd_drop=!random! %% 20"
    if !rnd_drop! equ 0 set "ctr_col[%%y]=1"
)
set "disp_line=%esc%[32m"
for /l %%y in (1,1,%col%) do set "disp_line=!disp_line!!disp_col[%%y]!"
<nul set /p "=%esc%[1T%esc%[1;1H"   %== scroll down and set cursor position to home ==%
echo(%disp_line%
goto matrix_loop

C

NCURSES version

Adaptation of Dan Ruscoe's C code. Header files added and code rearranged to suppress implicit declaration warnings.

Requires ncurses, install on Ubuntu as follows :

$ sudo apt install libncurses5-dev

Compile with ncurses flag :

$ cc digiRain.c -lncurses

And here's the code :

/**
 * Loosely emulates the "digital rain" effect from The Matrix.
 *
 * @author Dan Ruscoe <dan@ruscoe.org>
 */
#include <unistd.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <ncurses.h>

/* Time between row updates in microseconds.
   Controls the speed of the digital rain effect.
*/
#define ROW_DELAY 40000

/**
 * Gets a random integer within a given range.
 *
 * @param int min The low-end of the range.
 * @param int max The high-end of the range.
 *
 * @return int The random integer.
 */
int get_rand_in_range(int min, int max)
{
  return (rand() % ((max + 1) - min) + min);
}

int main(void)
{
  /* Basic seed for random numbers. */
  srand(time(NULL));

  /* Characters to randomly appear in the rain sequence. */
  char chars[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};

  int total_chars = sizeof(chars);

  /* Set up ncurses screen and colors. */
  initscr();
  noecho();
  curs_set(FALSE);

  start_color();
  init_pair(1, COLOR_GREEN, COLOR_BLACK);
  attron(COLOR_PAIR(1));

  int max_x = 0, max_y = 0;

  getmaxyx(stdscr, max_y, max_x);

  /* Create arrays of columns based on screen width. */

  /* Array containing the current row of each column. */
  int columns_row[max_x];

  /* Array containing the active status of each column.
     A column draws characters on a row when active.
  */
  int columns_active[max_x];

  int i;

  /* Set top row as current row for all columns. */
  for (i = 0; i < max_x; i++)
  {
    columns_row[i] = -1;
    columns_active[i] = 0;
  }

  while (1)
  {
    for (i = 0; i < max_x; i++)
    {
      if (columns_row[i] == -1)
      {
        /* If a column is at the top row, pick a
           random starting row and active status.
        */
        columns_row[i] = get_rand_in_range(0, max_y);
        columns_active[i] = get_rand_in_range(0, 1);
      }
    }

    /* Loop through columns and draw characters on rows. */
    for (i = 0; i < max_x; i++)
    {
      if (columns_active[i] == 1)
      {
        /* Draw a random character at this column's current row. */
        int char_index = get_rand_in_range(0, total_chars);
        mvprintw(columns_row[i], i, "%c", chars[char_index]);
      }
      else
      {
        /* Draw an empty character if the column is inactive. */
        mvprintw(columns_row[i], i, " ");
      }

      columns_row[i]++;

      /* When a column reaches the bottom row, reset to top. */
      if (columns_row[i] >= max_y)
      {
        columns_row[i] = -1;
      }

      /* Randomly alternate the column's active status. */
      if (get_rand_in_range(0, 1000) == 0)
      {
        columns_active[i] = (columns_active[i] == 0) ? 1 : 0;
      }
    }

    usleep(ROW_DELAY);
    refresh();
  }

  endwin();
  return 0;
}

Microsoft Windows console version

Single threaded

/*******************************************************************************
*
* Digital ASCII rain - the single thread variant.
* 2012 (C) by Author, 2020 GPL licensed for RossetaCode
*
*******************************************************************************/

#include <assert.h>    /* assertions */
#include <conio.h>     /* console operations */
#include <locale.h>    /* l10n and i18n */
#include <string.h>    /* operations on strings and memory blocks */
#include <process.h>   /* Microsoft Windows API for threads etc. */
#include <stdio.h>     /* standard i/o library */
#include <stdlib.h>    /* standard library with rand() function */
#include <time.h>      /* time(NULL) used as srand(time(NULL)) */
#include <windows.h>   /* just the Microsoft Windows main header for C */


/*
 * Global variables - you could use local variables instead... 
 * but then e.g. the memory for the buffer variable would be unnecessarily
 * allocated and released manifold, which would lead to a worse performance.
 */

HANDLE                     hStdOut;     /* the handle to console "out" */       
CONSOLE_SCREEN_BUFFER_INFO csbi;        /* numbers of rows, columns etc. */

PCHAR_INFO buffer = NULL;               /* an enough big buffer */
COORD bufferSize, bufferCoord;          /* the size of buffer etc. */


/*
 * A structure that holds data that is distinct for each column.
 */
struct Data
{
  DWORD      armed;  /* time in ms to synchronize */
  int        delay;  /* armed = current_time + delay */
  BOOL       show;   /* TRUE - draw, FALSE - erase */
  COORD      ncp;    /* position for drawing new characters */
  SMALL_RECT s, d;   /* source/destination regions for copy */
};

/* 
 * A function to generate random numbers from the range (a, b).  
 * NOTE: POSIX rand () is not thread safe, 
 * but we use secure rand() from MS runtime libraries.
 */

int rnd(int a, int b)
{
  return a + rand() % (b + 1 - a);
}

BOOL randomShow(void)
{
  return rnd(0, 99) < 65;
}

int randomDelay(void)
{
  return rnd(0, 150) + rnd(0, 150) + rnd(0, 150);
}

BOOL randomRegenerate(void)
{
  return rnd(0, 99) < 2;
}

void column_init(struct Data* data, int k)
{
  data->armed = 0;
  data->show  = randomShow();
  data->delay = randomDelay();

  data->s.Left   = k;
  data->s.Top    = 0;
  data->s.Bottom = bufferSize.Y - 2;
  data->s.Right  = k;

  data->d.Left   = data->s.Left;
  data->d.Top    = data->s.Top + 1;
  data->d.Right  = data->s.Right;
  data->d.Bottom = data->s.Bottom + 1;

  data->ncp.X = k;
  data->ncp.Y = 0;
}


void column_run(struct Data* data)
{
  char c;
  WORD a;
  DWORD result;

  /*
   * Shift down a column.
   */
  ReadConsoleOutput (hStdOut, buffer, bufferSize, bufferCoord, &data->s);
  WriteConsoleOutput(hStdOut, buffer, bufferSize, bufferCoord, &data->d); 

  /*
   * If show == TRUE then generate a new character. 
   * If show == FALSE write the space to erase.
   */
  if(data->show)
  {
    c = (rnd(1,100) <= 15) ? ' ' : rnd( 'a', 'z' );
    a = FOREGROUND_GREEN | ((rnd(1,100) >  10) ? 0 : FOREGROUND_INTENSITY);
  }
  else
  {
    c = ' ';
    a = FOREGROUND_GREEN;
  }

  WriteConsoleOutputCharacter(hStdOut, &c, 1, data->ncp, &result);
  WriteConsoleOutputAttribute(hStdOut, &a, 1, data->ncp, &result);

  /*
   * Randomly regenerate the delay and the visibility state of the column.
   */
  if(randomRegenerate()) data->show  = randomShow();
  if(randomRegenerate()) data->delay = randomDelay();

  data->armed = GetTickCount() + data->delay;
}


int main(int argc, char* argv[])
{
  int j;
  struct Data* table;

  srand((unsigned int)time(NULL));

  hStdOut = GetStdHandle( STD_OUTPUT_HANDLE );
  SetConsoleTitle("Digital ASCII rain");

  /*
   * An attempt to run in the full-screen mode.
   */
  if(argc == 1)
  {
    COORD coord;
    CONSOLE_CURSOR_INFO cci;
    cci.bVisible = FALSE;
    cci.dwSize   = 0;
    SetConsoleDisplayMode(hStdOut, CONSOLE_FULLSCREEN_MODE, &coord);
    SetConsoleCursorInfo(hStdOut, &cci);
  }

  GetConsoleScreenBufferInfo(hStdOut, &csbi );
  //SetConsoleTextAttribute(hStdOut, FOREGROUND_GREEN);

  bufferSize.X  = 1;
  bufferSize.Y  = csbi.dwSize.Y - 1;
  bufferCoord.X = 0;
  bufferCoord.Y = 0;
  buffer = (PCHAR_INFO)calloc(bufferSize.Y, sizeof(CHAR_INFO));
  assert(buffer != NULL);

  table = (struct Data*)calloc(csbi.dwSize.X, sizeof(struct Data));
  assert(table != NULL);

  for(j = 0; j < csbi.dwSize.X; j++) column_init(&table[j], j);

  /*
   * Main loop. Sleep(1) significally decreases the CPU load.
   */

  while(!_kbhit())
  {
    DWORD t = GetTickCount();
    for(j = 0; j < csbi.dwSize.X; j++)
      if(table[j].armed < t) column_run(&table[j]);
    Sleep(1);
  }

  free(table);
  free(buffer);

  return 0;
}

Multiple threads

/*******************************************************************************
*
* Digital ASCII rain - multithreaded.
* 2012 (C) by Author, 2020 GPL licensed for RossetaCode
*
*******************************************************************************/

#include <assert.h>    /* assertions */
#include <conio.h>     /* console operations */
#include <locale.h>    /* l10n and i18n */
#include <string.h>    /* operations on strings and memory blocks */
#include <process.h>   /* Microsoft Windows API for threads etc. */
#include <stdio.h>     /* standard i/o library */
#include <stdlib.h>    /* standard library with rand() function */
#include <time.h>      /* time(NULL) used as srand(time(NULL)) */
#include <windows.h>   /* just the Microsoft Windows main header for C */


//#define SYNCHRONIZED_INIT


/*
 * Global variables, common for all threads. 
 * The handle eventThreadInitialized is to synchronize threads initializations.
 */
#ifdef SYNCHRONIZED_INIT
HANDLE eventThreadInitialized;
#endif

BOOL                       loop = TRUE; /* FALSE - przerwać działanie */
HANDLE                     hStdOut;     /* uchwyt do konsoli "out" */       
CONSOLE_SCREEN_BUFFER_INFO csbi;        /* liczby wierszy i kolumn itd.*/


struct InitThreadData
{
  int      column;
  unsigned seed;
};


/* 
 * A function to generate random numbers from the range (a, b).  
 * NOTE: POSIX rand () is not thread safe, 
 * but we use secure rand() from MS runtime libraries.
 */
 
int rnd(int a, int b)
{
  return a + rand() % (b + 1 - a);
}
 
BOOL randomShow(void)
{
  return rnd(0, 99) < 65;
}

int randomDelay(void)
{
  return rnd(0,150) + rnd(0,150) + rnd(0,150);
}

BOOL randomRegenerate(void)
{
  return rnd(0,99) < 2;
}


/*
 * Update a single column.
 */
void one_column(void *arg)
{
  BOOL show; 
  int  k;
  char c;
  WORD a;
  int  delay;
  PCHAR_INFO buffer;
  COORD bufferSize, bufferCoord, newCharPosition;
  SMALL_RECT s, d;
  DWORD result;

  /* 
   * Retrieve the column number, initialize the (pseudo)random numbers
   * generator with a "private" seed, check assertions.
   */
  k = ((struct InitThreadData*)arg)->column;
  srand(((struct InitThreadData*)arg)->seed);
  assert(csbi.dwSize.X != 0 && csbi.dwSize.Y != 0);
  assert(0 <= k && k <= csbi.dwSize.X);

  show   = randomShow();
  delay  = randomDelay();

  bufferSize.X = 1;
  bufferSize.Y = csbi.dwSize.Y - 1;
  bufferCoord.X = 0;
  bufferCoord.Y = 0;

  buffer = (PCHAR_INFO)malloc(bufferSize.Y * sizeof(CHAR_INFO));
  assert( buffer != NULL );

  s.Left   = k;
  s.Top    = 0;
  s.Bottom = bufferSize.Y - 2;
  s.Right  = k;

  d.Left   = s.Left;
  d.Top    = s.Top + 1;
  d.Right  = s.Right;
  d.Bottom = s.Bottom + 1;

  newCharPosition.X = k;
  newCharPosition.Y = 0;
  
#ifdef SYNCHRONIZED_INIT
  SetEvent(eventThreadInitialized);
#endif

  /*
   * Main loop inside this one thread.
   */
  while(loop)
  {
    ReadConsoleOutput ( hStdOut, buffer, bufferSize, bufferCoord, &s);
    WriteConsoleOutput( hStdOut, buffer, bufferSize, bufferCoord, &d); 

    if(show)
    {
      c = (rnd(1,100) <= 15) ? ' ' : rnd( 'a', 'z' );
      a = FOREGROUND_GREEN | ((rnd(1,100) >  1) ? 0 : FOREGROUND_INTENSITY);
    }
    else
    {
      c = ' ';
      a = FOREGROUND_GREEN;
    }

    WriteConsoleOutputCharacter( hStdOut, &c, 1, newCharPosition, &result );
    WriteConsoleOutputAttribute( hStdOut, &a, 1, newCharPosition, &result );

    if(randomRegenerate())  show  = randomShow();
    if(randomRegenerate())  delay = randomDelay();

    Sleep( delay );
  }

  free(buffer);
}


int main(int argc, char* argv[])
{
  int j;
  struct InitThreadData *init = NULL;

  srand((time_t)time(NULL));

  hStdOut = GetStdHandle( STD_OUTPUT_HANDLE );
  SetConsoleTitle("MATRIX");

  if(argc == 1)
  {
    COORD coord;
    CONSOLE_CURSOR_INFO cci;

    cci.bVisible = FALSE;
    cci.dwSize   = 0;
    SetConsoleDisplayMode(hStdOut,CONSOLE_FULLSCREEN_MODE,&coord);
    SetConsoleCursorInfo(hStdOut,&cci);
  }

  GetConsoleScreenBufferInfo( hStdOut, &csbi );
  //SetConsoleTextAttribute(hStdOut,FOREGROUND_GREEN);

#ifdef SYNCHRONIZED_INIT
  eventThreadInitialized = CreateEvent(NULL,FALSE,FALSE,NULL);
  assert( eventThreadInitialized != NULL );
#endif

  init = (struct InitThreadData*)
          malloc(csbi.dwSize.X * sizeof(struct InitThreadData));
  assert( init != NULL );

  for(j = 0; j < csbi.dwSize.X; j++)
  {
    init[j].column = j;
    init[j].seed = rand();
    _beginthread(one_column, 0, (void*)&init[j]);
#ifdef SYNCHRONIZED_INIT
    WaitForSingleObject(eventThreadInitialized,INFINITE);
#endif
  }

  getchar();
  free(init);

#ifdef SYNCHRONIZED_INIT
  CloseHandle(eventThreadInitialized);
#endif SYNCHRONIZED_INIT

  return 0;
}

Fibers

/*******************************************************************************
*
* Digital ASCII rain - multithreaded.
* 2012 (C) by Author, 2020 GPL licensed for RossetaCode
*
*******************************************************************************/

#include <assert.h>    /* assertions */
#include <conio.h>     /* console operations */
#include <locale.h>    /* l10n and i18n */
#include <string.h>    /* operations on strings and memory blocks */
#include <process.h>   /* Microsoft Windows API for threads etc. */
#include <stdio.h>     /* standard i/o library */
#include <stdlib.h>    /* standard library with rand() function */
#include <time.h>      /* time(NULL) used as srand(time(NULL)) */
#include <windows.h>   /* just the Microsoft Windows main header for C */


/*
 * Global variables, shared by fibers.
 */

BOOL                       loop = TRUE; 
HANDLE                     hStdOut;         
CONSOLE_SCREEN_BUFFER_INFO csbi;        

LPVOID  mainFiber = NULL;

struct WorkingFiber
{
  int      column;
  DWORD    callAfter;
  unsigned seed;
  LPVOID   fiber;
}  *workingFibersTable = NULL;

/* 
 * A function to generate random numbers from the range (a, b).  
 * NOTE: POSIX rand () is not thread safe, 
 * but we use secure rand() from MS runtime libraries.
 */

int rnd(int a, int b)
{
  return a + rand() % (b + 1 - a);
}

BOOL randomShow(void)
{
  return rnd(0, 99) < 65;
}

int randomDelay(void)
{
  return rnd(0,150) + rnd(0,150) + rnd(0,150);
}

BOOL randomRegenerate(void)
{
  return rnd(0,99) < 2;
}


VOID CALLBACK one_column(void *arg)
{
  struct WorkingFiber *ptr;
  BOOL show; 
  int  k;
  char c;
  WORD a;
  int  delay;
  PCHAR_INFO buffer;
  COORD bufferSize, bufferCoord, newCharPosition;
  SMALL_RECT s, d;
  DWORD result;

  ptr = (struct WorkingFiber*)arg;
  k = ptr->column;
  ptr->callAfter = 0;
  srand(ptr->seed);
  assert(csbi.dwSize.X != 0 && csbi.dwSize.Y != 0);
  assert(0 <= k && k <= csbi.dwSize.X);

  show  = randomShow();
  delay = randomDelay();

  bufferSize.X = 1;
  bufferSize.Y = csbi.dwSize.Y - 1;
  bufferCoord.X = 0;
  bufferCoord.Y = 0;

  buffer = (PCHAR_INFO)malloc(bufferSize.Y * sizeof(CHAR_INFO));
  assert( buffer != NULL );

  s.Left        = k;
  s.Top         = 0;
  s.Bottom      = bufferSize.Y - 2;
  s.Right       = k;

  d.Left   = s.Left;
  d.Top    = s.Top + 1;
  d.Right  = s.Right;
  d.Bottom = s.Bottom + 1;

  newCharPosition.X = k;
  newCharPosition.Y = 0;
  
  while(loop)
  {
    ReadConsoleOutput ( hStdOut, buffer, bufferSize, bufferCoord, &s);
    WriteConsoleOutput( hStdOut, buffer, bufferSize, bufferCoord, &d); 

    if(show)
    {
      c = (rnd(1,100) <= 15) ? ' ' : rnd( 'a', 'z' );
      a = FOREGROUND_GREEN | ((rnd(1,100) >  1) ? 0 : FOREGROUND_INTENSITY);
    }
    else
    {
      c = ' ';
      a = FOREGROUND_GREEN;
    }

    WriteConsoleOutputCharacter( hStdOut, &c, 1, newCharPosition, &result );
    WriteConsoleOutputAttribute( hStdOut, &a, 1, newCharPosition, &result );

    if(randomRegenerate())  show  = randomShow();
    if(randomRegenerate())  delay = randomDelay();

    ptr->callAfter = GetTickCount() + delay;
    SwitchToFiber(mainFiber);
  }

  free(buffer);
}


int main(int argc, char* argv[])
{
  int j;

  srand((unsigned int)time(NULL));

  hStdOut = GetStdHandle( STD_OUTPUT_HANDLE );
  SetConsoleTitle("MATRIX - FIBERS");

  if(argc == 1)
  {
    COORD coord;
    CONSOLE_CURSOR_INFO cci;

    cci.bVisible = FALSE;
    cci.dwSize   = 0;
    SetConsoleDisplayMode(hStdOut,CONSOLE_FULLSCREEN_MODE,&coord);
    SetConsoleCursorInfo(hStdOut,&cci);
  }

  GetConsoleScreenBufferInfo( hStdOut, &csbi );
  //SetConsoleTextAttribute(hStdOut,FOREGROUND_GREEN);

  mainFiber = ConvertThreadToFiber(NULL);
  assert( mainFiber != NULL );

  workingFibersTable = (struct WorkingFiber*)
                       calloc(csbi.dwSize.X, sizeof(struct WorkingFiber));
  assert( workingFibersTable != NULL );

  for(j = 0; j < csbi.dwSize.X; j++)
  {
    workingFibersTable[j].column = j;
    workingFibersTable[j].callAfter = 0;
    workingFibersTable[j].seed = rand();
    workingFibersTable[j].fiber = CreateFiber( 0, one_column, &workingFibersTable[j] );
  }

  loop = TRUE;
  while(!_kbhit())
  {
    DWORD t = GetTickCount();
    for(j = 0; j < csbi.dwSize.X; j++)
      if(workingFibersTable[j].callAfter < t)
        SwitchToFiber( workingFibersTable[j].fiber );
    Sleep(1);
  }

  loop = FALSE;
  for(j = 0; j < csbi.dwSize.X; j++)
  {
    SwitchToFiber( workingFibersTable[j].fiber );
    DeleteFiber(workingFibersTable[j].fiber);
  }

  free(workingFibersTable);

  return 0;
}

Common Lisp

Works with: SBCL

Runs in the terminal (using the Ncurses C library and the croatoan Lisp wrapper).

(defun matrix-digital-rain ()
  (with-screen (scr :input-echoing nil :input-blocking nil :cursor-visible nil)
    (let* ((width (width scr))
           (height (height scr))
           ;; start at a random height in each column.
           (positions (loop repeat width collect (random height)))
           ;; run each column at a random speed.
           (speeds (loop repeat width collect (random 4))))
      ;; generate a random ascii char
      (flet ((randch () (+ 64 (random 58))))
        ;; hit the q key to exit the main loop.
        (bind scr #\q 'exit-event-loop)
        (bind scr nil
          (lambda (win event)
            (loop for col from 0 to (1- width) do
              (loop repeat (nth col speeds) do
                ;; position of the first point in the current column
                (let ((pos (nth col positions)))
                  (setf (attributes win) '(:bold))
                  (setf (fgcolor win) :green)
                  (add win (randch) :y (mod pos height) :x col :fgcolor :white)
                  (add win (randch) :y (mod (- pos 1) height) :x col)
                  (add win (randch) :y (mod (- pos 2) height) :x col)
                  (setf (attributes win) '())
                  (add win (randch) :y (mod (- pos 3) height) :x col)
                  ;; overwrite the last char half the height from the first char.
                  (add win #\space  :y (mod (- pos (floor height 2)) height) :x col)
                  (refresh win)
                  ;; advance the current column
                  (setf (nth col positions) (mod (+ pos 1) height))))))))
      (setf (frame-rate scr) 20)
      (run-event-loop scr))))
Sample output:

https://i.imgur.com/17b36O3.png

Go

Library: goncurses

This is a translation of the C code here which uses the ncurses library.

Rather than pressing Ctrl+C to stop the program, I've added code so that it stops automatically after 1 minute and restores the terminal to its original state.

package main

import (
    gc "github.com/rthornton128/goncurses"
    "log"
    "math/rand"
    "time"
)

// Time between row updates in microseconds.
// Controls the speed of the digital rain effect.
const rowDelay = 40000

func main() {
    start := time.Now()
    rand.Seed(time.Now().UnixNano())

    // Characters to randomly appear in the rain sequence.
    chars := []byte("0123456789")
    totalChars := len(chars)

    // Set up ncurses screen and colors.
    stdscr, err := gc.Init()
    if err != nil {
        log.Fatal("init", err)
    }
    defer gc.End()

    gc.Echo(false)
    gc.Cursor(0)

    if !gc.HasColors() {
        log.Fatal("Program requires a colour capable terminal")
    }

    if err := gc.StartColor(); err != nil {
        log.Fatal(err)
    }

    if err := gc.InitPair(1, gc.C_GREEN, gc.C_BLACK); err != nil {
        log.Fatal("InitPair failed: ", err)
    }
    stdscr.ColorOn(1)
    maxY, maxX := stdscr.MaxYX()

    /* Create slices of columns based on screen width. */

    // Slice containing the current row of each column.
    columnsRow := make([]int, maxX)

    // Slice containing the active status of each column.
    // A column draws characters on a row when active.
    columnsActive := make([]int, maxX)

    // Set top row as current row for all columns.
    for i := 0; i < maxX; i++ {
        columnsRow[i] = -1
        columnsActive[i] = 0
    }

    for {
        for i := 0; i < maxX; i++ {
            if columnsRow[i] == -1 {
                // If a column is at the top row, pick a
                // random starting row and active status.
                columnsRow[i] = rand.Intn(maxY + 1)
                columnsActive[i] = rand.Intn(2)
            }
        }

        // Loop through columns and draw characters on rows.
        for i := 0; i < maxX; i++ {
            if columnsActive[i] == 1 {
                // Draw a random character at this column's current row.
                charIndex := rand.Intn(totalChars)
                stdscr.MovePrintf(columnsRow[i], i, "%c", chars[charIndex])
            } else {
                // Draw an empty character if the column is inactive.
                stdscr.MovePrintf(columnsRow[i], i, "%c", ' ')
            }

            columnsRow[i]++

            // When a column reaches the bottom row, reset to top.
            if columnsRow[i] >= maxY {
                columnsRow[i] = -1
            }

            // Randomly alternate the column's active status.
            if rand.Intn(1001) == 0 {
                if columnsActive[i] == 0 {
                    columnsActive[i] = 1
                } else {
                    columnsActive[i] = 0
                }
            }
        }
        time.Sleep(rowDelay * time.Microsecond)
        stdscr.Refresh()
        elapsed := time.Since(start)
        // Stop after 1 minute.
        if elapsed.Minutes() >= 1 {
            break
        }
    }
}

J

This implementation was written for jqt under j903, after studying https://youtu.be/MvEXkd3O2ow

Some key issues are the (deliberate) relatively low resolution of the screen in the movie, a somewhat slow update rate and some variation over time in the update rate of the screen. This implementation is, of course, only an approximation...

require'gl2'
coinsert'jgl2'

junk=: 7 u:;48 65 16b30a1(+i.)&.>10 26 90
sz=:40 25
len=: <.1.4*{:sz
heat=: (224 255 255),~(<.0.5+255*(%>./)(-<./)^>:(% >./)i.len)*/0 1 0

cols=: i.0
rows=: i.0
scale=: 24
live=: (#heat)#<i.0 3

rain_timer=: {{
  try.
    wd 'psel rain'
    glsel 'green'
    glfill 0 0 0 255
    glfont font=.'courier ',":0.8*scale
    upd=. 0>._3++/?2 2 2 2 4
    cols=: cols,upd{.(?~{.sz)-.(-<.0.3*{:sz){.cols
    rows=: (#cols){.rows
    live=: }.live,<(scale*cols,.rows),.?(#cols)##junk
    for_p. live do.
      gltextcolor glrgb p_index{heat
      if.p_index=<:#live do.
        glfont font,' bold'
      end.
      for_xyj.;p do.
        gltextxy 2{.xyj
        gltext 8 u:junk{~{:xyj
      end.
    end.
    glpaintx''
    keep=: rows<{:sz-1
    cols=: keep#cols
    rows=: keep#rows+1
    EMPTY
  catch.
    wd'ptimer 0'
  end.
}}

wd rplc&('DIMS';":scale*sz) {{)n
  pc rain closeok;
  setp wh DIMS;
  cc green isidraw flush;
  pshow;
  ptimer 100
}}
File:J-matrix-digital-rain.png

Notes:

ptimer 100 to roughly match the update rate used in the matrix movie.

In the movie, the display was somewhat pixelated, and had some other artifacts which were characteristic of cathode display tubes. The font support we use here does not emulate all of that.

Conceptually, we are emulating an emulation of a cathode ray tube with a long phosphor persistence time. Thus, there's an initial "burst" of light when the phosphor is being painted followed by a lingering glow which gradually fades out. Here, we use a light cyan to represent the initial paint event and fading shades of green to represent the fading phosphors. To better approximate the phosphor persistence mechanism, we have intensity fall off exponentially (and then we adjust the numeric range of the result so it still fades from our brightest green to black).

JavaScript

El código es de Christian Behler (christian@pingpoli.de)

var tileSize = 20;
// a higher fade factor will make the characters fade quicker
var fadeFactor = 0.05;

var canvas;
var ctx;

var columns = [];
var maxStackHeight;

function init() {
	canvas = document.getElementById('canvas');
	ctx = canvas.getContext('2d');

    // https://developer.mozilla.org/en-US/docs/Web/API/ResizeObserver
    const resizeObserver = new ResizeObserver(entries =>
    {
        for (let entry of entries)
        {
            if (entry.contentBoxSize)
            {
                // Firefox implements `contentBoxSize` as a single content rect, rather than an array
                const contentBoxSize = Array.isArray(entry.contentBoxSize) ? entry.contentBoxSize[0] : entry.contentBoxSize;

                canvas.width = contentBoxSize.inlineSize;
                canvas.height = window.innerHeight;

                initMatrix();
            }
        }
    });

    // observe the size of the document
    resizeObserver.observe(document.documentElement);

	// start the main loop
	tick();
}

function initMatrix() {
    columns = [];

    maxStackHeight = Math.ceil(canvas.height/tileSize);

    // divide the canvas into columns
    for (let i = 0 ; i < canvas.width/tileSize ; ++i) {
        var column = {};
        // save the x position of the column
        column.x = i*tileSize;
        // create a random stack height for the column
        column.stackHeight = 10+Math.random()*maxStackHeight;
        // add a counter to count the stack height
        column.stackCounter = 0;
        // add the column to the list
        columns.push(column);
    }
}

function draw() {
    // draw a semi transparent black rectangle on top of the scene to slowly fade older characters
    ctx.fillStyle = "rgba(0 , 0 , 0 , "+fadeFactor+")";
    ctx.fillRect(0 , 0 , canvas.width , canvas.height);

    ctx.font = (tileSize-2)+"px monospace";
    ctx.fillStyle = "rgb(0 , 255 , 0)";
    for (let i = 0 ; i < columns.length ; ++i) {
        // pick a random ascii character (change the 94 to a higher number to include more characters)
        var randomCharacter = String.fromCharCode(33+Math.floor(Math.random()*94));
        ctx.fillText(randomCharacter , columns[i].x , columns[i].stackCounter*tileSize+tileSize);

        // if the stack is at its height limit, pick a new random height and reset the counter
        if (++columns[i].stackCounter >= columns[i].stackHeight)
        {
            columns[i].stackHeight = 10+Math.random()*maxStackHeight;
            columns[i].stackCounter = 0;
        }
    }
}

// MAIN LOOP
function tick() {	
    draw();
    setTimeout(tick , 50);
}

var b_isFullscreen = false;

function fullscreen() {
    var elem = document.documentElement;
    if (elem.requestFullscreen) {
        elem.requestFullscreen();
    }
    else if (elem.webkitRequestFullscreen) { 
        elem.webkitRequestFullscreen(); // Safari
    }
    else if (elem.msRequestFullscreen) { 
        elem.msRequestFullscreen(); // IE11
    }
}

function exitFullscreen() {
    if (document.exitFullscreen) {
        document.exitFullscreen();
    }
    else if (document.webkitExitFullscreen) {
        document.webkitExitFullscreen(); // Safari
    }
    else if (document.msExitFullscreen) {
        document.msExitFullscreen(); // IE11
    }
}

function toggleFullscreen() {
    if (!b_isFullscreen) {
        fullscreen();
        b_isFullscreen = true;
    }
    else {
        exitFullscreen();
        b_isFullscreen = false;
    }
}

function updateTileSize() {
    tileSize = Math.min(Math.max(document.getElementById("tileSize").value , 10) , 100);
    initMatrix();
}

function updateFadeFactor() {
    fadeFactor = Math.min(Math.max(document.getElementById("fadeFactor").value , 0.0) , 1.0);
    initMatrix();
}

Html to test:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <script src="The_Matrix_rain.js"></script>
    <title>The Matrix rain</title>
    <style>
      body {padding: 50px;width: 50%;box-shadow: 0 0 15px 0 rgba(0, 0, 0, 0.25);margin: 15px auto;font-family: "Gill Sans", "Gill Sans MT", Calibri, "Trebuchet MS", sans-serif;letter-spacing: 1px;}
      a {color: #00aadd;text-decoration: none;}
      input {width: 50px;text-align: center;}
      ul {list-style: none;padding: 0;margin: 0;width: 25%;margin: auto;border: 1px solid #aaa;}
      li {text-align: center;background-color: #eaeaea;}
      li:nth-child(even) {background: #fff;}
    </style>
  </head>
  <body onload="init();" style="margin: 0; padding: 0; background-color:#000000;">
  <canvas id="canvas" style="display:block;margin:0 auto;" width="1920" height="955"></canvas>
  <div id="options" style="position: absolute; right: 10px; bottom: 10px; padding: 5px; background-color: #aaaaaa; font-family: monospace;">
  <button onclick="toggleFullscreen()" style="font-family: monospace;">Toggle Fullscreen</button>
  <table>
    <tbody><tr>
      <td>Tile Size</td>
      <td><input type="number" id="tileSize" value="20" onchange="updateTileSize()" onkeyup="updateTileSize()" style="width: 80px; font-family: monospace; outline: none;" min="10" max="100" step="1"></td>
    </tr>
    <tr>
      <td>Fade Factor</td>
      <td><input type="number" id="fadeFactor" value="0.05" onchange="updateFadeFactor()" onkeyup="updateFadeFactor()" style="width: 80px; font-family: monospace; outline: none;" min="0" max="1" step="0.01"></td>
    </tr>
  </tbody></table>
  </div>
  </body>
</html>

Julia

The font used is based on Leonardo da Vinci's notebooks. The font is freely obtainable at https://www.wfonts.com/font/leonardos-mirrorwriting.

using Gtk, Colors, Cairo
import Base.iterate, Base.IteratorSize, Base.IteratorEltype

const caps = [c for c in "ABCDEFGHIJKLMNOPQRSTUVWXYZ"]
startfall() = rand() < 0.2
endfall() = rand() < 0.2
startblank() = rand() < 0.1
endblank() = rand() < 0.05
bechangingchar() = rand() < 0.03

struct RainChars chars::Vector{Char} end
Base.IteratorSize(s::RainChars) = Base.IsInfinite()
Base.IteratorEltype(s::RainChars) = Char
function Base.iterate(rain::RainChars, state = (true, false, 0))
    c = '\0'
    isfalling, isblank, blankcount = state
    if isfalling # falling, so feed the column
        if isblank
            c = ' '
            ((blankcount += 1) > 12) && (isblank = endblank())
        else
            c = bechangingchar() ? '~' : rand(rain.chars)
            isblank, blankcount = startblank(), 0
        end
        endfall() && (isfalling = false)
    else
        isfalling = startfall()
    end   
    return c, (isfalling, isblank, blankcount)
end

function digitalrain()
    mapwidth, mapheight, fontpointsize = 800, 450, 14
    windowmaxx = div(mapwidth, Int(round(fontpointsize * 0.9)))
    windowmaxy = div(mapheight, fontpointsize)
    basebuffer = fill(' ', windowmaxy, windowmaxx)
    bkcolor, rcolor, xcolor = colorant"black", colorant"green", colorant"limegreen"

    columngenerators = [Iterators.Stateful(RainChars(caps)) for _ in 1:windowmaxx]

    win = GtkWindow("Digital Rain Effect", mapwidth, mapheight) |>
        (GtkFrame() |> (can = GtkCanvas()))
    set_gtk_property!(can, :expand, true)

    draw(can) do widget
        ctx = Gtk.getgc(can)
        select_font_face(ctx, "Leonardo\'s mirrorwriting", Cairo.FONT_SLANT_NORMAL,
            Cairo.FONT_WEIGHT_BOLD)
        set_font_size(ctx, fontpointsize)
        set_source(ctx, bkcolor)
        rectangle(ctx, 0, 0, mapwidth, mapheight)
        fill(ctx)
        set_source(ctx, rcolor)
        for i in 1:size(basebuffer)[1], j in 1:size(basebuffer)[2]
            move_to(ctx, j * fontpointsize * 0.9, i * fontpointsize)
            c = basebuffer[i, j]
            if c == '~'
				set_source(ctx, xcolor)
                show_text(ctx, String([rand(caps)]))
				set_source(ctx, rcolor)
            else
                show_text(ctx, String([c]))
            end
        end
    end

    while true
        for col in 1:windowmaxx
            c = popfirst!(columngenerators[col])
            if c != '\0'
                basebuffer[2:end, col] .= basebuffer[1:end-1, col]
                basebuffer[1, col] = c
            end
        end
        draw(can)
        Gtk.showall(win)
        sleep(0.05)
    end
end

digitalrain()

Locomotive Basic

10 mode 0:defint a-z:randomize time:ink 0,0:ink 1,26:ink 2,19:border 0
20 dim p(20):mm=5:dim act(mm):for i=1 to mm:act(i)=rnd*19+1:next
30 md=mm-2:dim del(md):for i=1 to md:del(i)=rnd*19+1:next
40 for i=1 to mm:x=act(i):locate x,p(x)+1:pen 1:print chr$(rnd*55+145);
50 if p(x)>0 then locate x,p(x):pen 2:print chr$(rnd*55+145);
60 p(x)=p(x)+1:if p(x)=25 then locate x,25:pen 2:print chr$(rnd*55+145);:p(x)=0:act(i)=rnd*19+1
70 next
80 for i=1 to md:x=del(i):locate x,p(x)+1:print " ";
90 p(x)=p(x)+1:if p(x)=25 then p(x)=0:del(i)=rnd*19+1
100 next
110 goto 40

The program above runs at an acceptable speed on a 4 MHz Z80, but can be made much faster by using the CPCBasic JavaScript emulator. CPCBasic also adds an 80x50 display mode ("mode 3") which real CPC hardware lacks. Changing screen size from 20x25 to 80x50 and adding a delay with "frame" in line 100 results in a far more impressive display in CPCBasic:

10 mode 3:defint a-z:randomize time:ink 0,0:ink 1,26:ink 2,19:border 0
20 dim p(80):mm=12:dim act(mm):for i=1 to mm:act(i)=rnd*79+1:next
30 md=mm-2:dim del(md):for i=1 to md:del(i)=rnd*79+1:next
40 for i=1 to mm:x=act(i):locate x,p(x)+1:pen 1:print chr$(rnd*55+145);
50 if p(x)>0 then locate x,p(x):pen 2:print chr$(rnd*55+145);
60 p(x)=p(x)+1:if p(x)=50 then locate x,50:pen 2:print chr$(rnd*55+145);:p(x)=0:act(i)=rnd*79+1
70 next
80 for i=1 to md:x=del(i):locate x,p(x)+1:print " ";
90 p(x)=p(x)+1:if p(x)=50 then p(x)=0:del(i)=rnd*79+1
100 next:frame
110 goto 40

Mathematica/Wolfram Language

SeedRandom[1234];
ClearAll[ColorFunc]
chars = RandomSample[Flatten[CharacterRange @@@ Partition[Characters["\[CapitalAlpha]\[CapitalPi]ЀѵҊԯ\:03e2\:03efヲンⲀ⳩\[ForAll]∗℀℺⨀⫿"], 2]]];
charlen = Length[chars];
fadelength = 6;
ColorFunc[fade_] := ColorFunc[fade] = Blend[{Black, Green}, fade/fadelength]
rows = 30;
cols = 50;
n = 10;
trailpos = {RandomInteger[{1, cols}, n], RandomInteger[{1, rows}, n]} // Transpose;
trailchars = RandomInteger[{1, Length[chars]}, n];
charmap = ConstantArray[".", {rows, cols}];
fade = ConstantArray[5, {rows, cols}];
indices = MapIndexed[#2 &, fade, {2}];
Dynamic[Graphics[{txts}, PlotRange -> {{1, cols}, {1, rows}}, PlotRangePadding -> 1, Background -> Black]]
Do[
 trailpos[[All, 2]] += 1;
 fade = Ramp[fade - 1];
 trailchars = Mod[trailchars + 1, charlen, 1];
 Do[
  If[trailpos[[i, 2]] >= rows,
   trailpos[[i, 2]] = 1;
   trailpos[[i, 1]] = RandomInteger[{1, cols}];
   ];
  charmap[[trailpos[[i, 2]], trailpos[[i, 1]]]] = 
   chars[[trailchars[[i]]]];
  fade[[trailpos[[i, 2]], trailpos[[i, 1]]]] = fadelength
  ,
  {i, n}
  ];
 txts = MapThread[If[#2 > 0, Text[Style[#1, ColorFunc[#2]], {#1, rows - #2 + 1} & @@ Reverse[#3]], {}] &, {charmap, fade, indices}, 2];
 Pause[0.1]
 ,
 {1000}
]
Output:

Outputs a animating graphic of the matrix digital rain.

Nim

Translation of: C
Library: nim-ncurses
import os, random, sequtils
import ncurses

const RowDelay = 40   # In milliseconds.

proc exit() {.noconv.} =
  endwin()
  quit QuitSuccess

proc run() =

  const
    Chars = "0123456789"    # Characters to randomly appear in the rain sequence.

  let stdscr = initscr()
  noEcho()
  cursSet(0)
  startColor()
  initPair(1, COLOR_GREEN, COLOR_BLACK)
  attron(COLOR_PAIR(1).cint)

  var width, height: cint
  stdscr.getmaxyx(height, width)
  let maxX = width - 1
  let maxY = height - 1

  # Create arrays of columns based on screen width.

  # Array containing the current row of each column.
  # Set top row as current row for all columns.
  var columnsRow = repeat(cint -1, width)

  # Array containing the active status of each column.
  # A column draws characters on a row when active.
  var columnsActive = newSeq[bool](width)


  setControlCHook(exit)
  while true:

    for i in 0..maxX:
      if columnsRow[i] == -1:
        # If a column is at the top row, pick a random starting row and active status.
        columnsRow[i] = cint(rand(maxY))
        columnsActive[i] = bool(rand(1))

    # Loop through columns and draw characters on rows.
    for i in 0..maxX:
      if columnsActive[i]:
        # Draw a random character at this column's current row.
        let charIndex = rand(Chars.high)
        mvprintw(columnsRow[i], i, "%c", Chars[charIndex])
      else:
        # Draw an empty character if the column is inactive.
        mvprintw(columnsRow[i], i, " ")

      inc columnsRow[i]
      # When a column reaches the bottom row, reset to top.
      if columnsRow[i] > maxY: columnsRow[i] = -1

      # Randomly alternate the column's active status.
      if rand(999) == 0: columnsActive[i] = not columnsActive[i]

    sleep(RowDelay)
    refresh()

run()

Perl

Probably shouldn't, but until someone posts something better... here's something somewhat relevant I wrote back in 2006.

Follow the bouncing Neo!

#!/user/bin/perl

use strict;
use warnings;
use Tk;

my $delay      = 50;                            # milliseconds
my $fade       = 8;                             # number of characters to "fade"
my $base_color = '#004000';                     # dark green
my $fontname   = 'Times';                       # Whatever
my $fontsize   = 12;                            # point size
my $font       = "{$fontname} $fontsize bold";
my @objects;

my ( $xv, $yv ) = ( 0, 0 );

my $top = MainWindow->new();

$top->geometry('800x600');

my $run = 1;

$top->protocol( 'WM_DELETE_WINDOW' => sub { $run = 0; } );

my @letters = ( 'A' .. 'Z', 'a' .. 'z', '0' .. '9' );

my $canvas = $top->Canvas(
    -background => 'black'
)->pack(
    -fill   => 'both',
    -expand => 'y'
);

my $testch = $canvas->createText(
    100, 100,
    -text => 'o',
    -fill => 'black',
    -font => $font
);

$top->update;

my @coords = $canvas->bbox($testch);

$canvas->delete($testch);

my $lwidth  = $coords[2] - $coords[0];
my $lheight = ( $coords[3] - $coords[1] ) * .8;
my $cols    = int $canvas->width / $lwidth;
my $rows    = int $canvas->height / $lheight;

for my $y ( 0 .. $rows ) {
    for my $x ( 0 .. $cols ) {
        $objects[$x][$y] = $canvas->createText(
            $x * $lwidth, $y * $lheight,
            -text => $letters[ int rand @letters ],
            -fill => $base_color,
            -font => $font
        );
    }
}

my $neo_image = $top->Photo( -data => neo() );

my $neo = $canvas->createImage(
    $canvas->width / 2,
    $canvas->height / 2,
    -image => $neo_image
);

while ($run) {
    drop('Nothing Like The Matrix');
}
exit;

MainLoop;

sub drop {
    my @phrase = split //, reverse shift;
    my $x = int rand $cols;
    my @orig;
    for my $y ( 0 .. $rows ) {
        $orig[$y] = $canvas->itemcget( $objects[$x][$y], '-text' );
    }
    for my $y ( 0 .. $rows + @phrase + $fade ) {
        for my $letter ( 0 .. @phrase ) {
            last if ( $y - $letter < 0 );
            $canvas->itemconfigure(
                $objects[$x][ $y - $letter ],
                -text => $phrase[$letter],
                -fill => "#00FF00"
            );
        }
        if ( $y > @phrase ) {
            $canvas->itemconfigure(
                $objects[$x][ $y - @phrase ],
                -text => $orig[ $y - @phrase ],
                -fill => "#009000"
            );
        }
        if ( $y > @phrase + 2 ) {
            $canvas->itemconfigure( $objects[$x][ $y - @phrase - int ($fade / 2) ],
                -fill => "#006000" );
            $canvas->itemconfigure( $objects[$x][ $y - @phrase - $fade + 1 ],
                -fill => $base_color );
        }
        last unless $run;
        $top->after($delay);
        neo_move();
        $top->update;
    }
}

sub neo_move {
    $xv += ( ( rand 2 ) - 1 > 0 ) ? 1 : -1;
    $yv += ( ( rand 2 ) - 1 > 0 ) ? 1 : -1;
    my ( $x, $y ) = $canvas->coords($neo);
    $xv = -$xv if ( ( $x < 0 ) or ( $x > $canvas->width ) );
    $yv = -$yv if ( ( $y < 0 ) or ( $y > $canvas->height ) );
    $canvas->move( $neo, $xv, $yv );
}

sub neo {
return '
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';
}

Another Perl Solution

#!/usr/bin/perl

use strict; # http://www.rosettacode.org/wiki/Matrix_Digital_Rain
use warnings;
use Tk;
use List::Util qw( shuffle );

my ($rows, $cols) = (20, 40);
my @text = shuffle 'a'..'z', 'A'..'Z';
my $n = 0;

my $mw = MainWindow->new;
$mw->geometry( '+850+300' );
my $c = $mw->Canvas( -width => $cols * 10, -height => $rows * 20,
  -bg => 'black',
  )->pack;
$c->Tk::bind('<ButtonRelease-1>' => sub { $mw->destroy } );

my @queue = [ 100, 0, 255, 'A' ]; # [ x, y, color, letter ]
$mw->after( 5, \&step );
MainLoop;

sub step
  {
  $c->delete('all');
  my @new = [ 10 * int rand $cols, 0, 255, $text[++$n % @text] ];
  for ( @queue )
    {
    my $color = $_->[2] == 255 ? '#ffffff' : sprintf '#00%02x00', $_->[2];
    $c->createText($_->[0], $_->[1],
      -font => '10x20', -text => $_->[3], -fill => $color );
    $_->[2] == 255 and push @new, [ $_->[0], $_->[1] + 20, 255, $_->[3] ];
    $_->[2] -= 13;
    }
  @queue = grep $_->[2] > 0 && $_->[1] < $rows * 20, @queue, @new;
  $mw->after( 63, \&step );
  }

Phix

Library: Phix/pGUI
Library: Phix/online

You can run this online here.

--
-- demo\rosetta\Matrix_Digital_Rain.exw
--
with javascript_semantics
sequence sushii = {},   -- w x h of unicode char strings
         colours,       --  """  of their fading colours
         droplets       -- w column droplets, or zeroes

include pGUI.e

Ihandle dlg, canvas, timer
cdCanvas cddbuffer, cdcanvas

procedure rain(integer w,h)
    for x=1 to w do
        integer y = droplets[x]
        if y or rand(40)=1 then
            if y<h then
                droplets[x] = y+1
                sushii[y+1][x] = utf32_to_utf8({0x30A0 + rand(96)})
                colours[y+1][x] = CD_WHITE
            end if
            if y then
                bool clear_droplet = true
                if colours[y][x]=CD_WHITE then
                    colours[y][x] = #00F800 -- (CD_GREEN to nearest #800)
                    clear_droplet = false
                    y -= 1
                end if
                while y>=1 do
                    integer cy = colours[y][x]
                    if cy=0 then exit end if
                    clear_droplet = false
                    cy -= #000800
                    colours[y][x] = cy
                    y -= 1
                end while
                if clear_droplet then
                    droplets[x] = 0
                end if
            end if
        end if
    end for
end procedure

function redraw_cb(Ihandle /*ih*/, integer /*posx*/, /*posy*/)
    integer {w,h} = IupGetIntInt(canvas, "DRAWSIZE"),
            {dx,dy} = cdCanvasGetTextSize(cddbuffer, "W")
    w = max(1,floor(w/dx))
    h = max(1,floor(h/dy))
    if length(sushii)!=h
    or length(sushii[1])!=w then
        sushii = repeat(repeat(" ",w),h)
        colours = repeat(repeat(CD_BLACK,w),h)
        droplets = repeat(0,w)
    end if
    cdCanvasActivate(cddbuffer)
    cdCanvasClear(cddbuffer)
    rain(w,h)
    for x=1 to w do
        for y=1 to h do
            if colours[y][x] then
                cdCanvasSetForeground(cddbuffer, colours[y][x])
                cdCanvasText(cddbuffer,x*dx, (h-y)*dy, sushii[y][x]) 
            end if
        end for
    end for
    cdCanvasFlush(cddbuffer)
    return IUP_DEFAULT
end function

function timer_cb(Ihandle /*ih*/)
    IupUpdate(canvas)
    return IUP_IGNORE
end function

function map_cb(Ihandle ih)
    cdcanvas = cdCreateCanvas(CD_IUP, ih)
    cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas)
    cdCanvasSetBackground(cddbuffer, CD_BLACK)
    return IUP_DEFAULT
end function

procedure main()
    IupOpen()
    IupSetGlobal("UTF8MODE","YES") 

    canvas = IupCanvas("RASTERSIZE=640x480")
    IupSetCallbacks(canvas, {"MAP_CB", Icallback("map_cb"),
                             "ACTION", Icallback("redraw_cb")})

    timer = IupTimer(Icallback("timer_cb"), 50)

    dlg = IupDialog(canvas,`TITLE="Matrix Digital Rain"`)

    IupShow(dlg)
    IupSetAttribute(canvas, "RASTERSIZE", NULL)
    if platform()!=JS then
        IupMainLoop()
        IupClose()
    end if
end procedure

main()

Python

import curses
import random
import time

"""

Based on C ncurses version

http://rosettacode.org/wiki/Matrix_Digital_Rain#NCURSES_version

"""

"""
Time between row updates in seconds
Controls the speed of the digital rain effect.
"""

ROW_DELAY=.0001

def get_rand_in_range(min, max):
    return random.randrange(min,max+1)

try:
    # Characters to randomly appear in the rain sequence.
    chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
    
    total_chars = len(chars)
        
    stdscr = curses.initscr()
    curses.noecho()
    curses.curs_set(False)
        
    curses.start_color()
    curses.init_pair(1, curses.COLOR_GREEN, curses.COLOR_BLACK)
    stdscr.attron(curses.color_pair(1))
    
    max_x = curses.COLS - 1
    max_y = curses.LINES - 1
    
         
    # Create arrays of columns based on screen width.
    
    # Array containing the current row of each column.
    
    columns_row = []
    
    # Array containing the active status of each column.
    # A column draws characters on a row when active.
    
    columns_active = []
    
    for i in range(max_x+1):
        columns_row.append(-1)
        columns_active.append(0)
        
    while(True):
        for i in range(max_x):
            if columns_row[i] == -1:
                # If a column is at the top row, pick a
                # random starting row and active status.
                columns_row[i] = get_rand_in_range(0, max_y)
                columns_active[i] = get_rand_in_range(0, 1)
     
        # Loop through columns and draw characters on rows
        
        for i in range(max_x):
            if columns_active[i] == 1:
                # Draw a random character at this column's current row.
                char_index = get_rand_in_range(0, total_chars-1)
                #mvprintw(columns_row[i], i, "%c", chars[char_index])                
                stdscr.addstr(columns_row[i], i, chars[char_index])
            else:
                # Draw an empty character if the column is inactive.
                #mvprintw(columns_row[i], i, " ");
                stdscr.addstr(columns_row[i], i, " ");
                
     
            columns_row[i]+=1
     
            # When a column reaches the bottom row, reset to top.
            if columns_row[i] >= max_y:
                columns_row[i] = -1
    
            # Randomly alternate the column's active status.
            if get_rand_in_range(0, 1000) == 0:
                if columns_active[i] == 0:      
                    columns_active[i] = 1
                else:
                    columns_active[i] = 0
     
            time.sleep(ROW_DELAY)
            stdscr.refresh()
    
except KeyboardInterrupt as err:
    curses.endwin()

Racket

Translation of: Raku
#lang racket

(define codes '((Α Π) (Ѐ ѵ) (Ҋ ԯ) (Ϣ ϯ) ( ) ( ) ( ) ( ) ( ⫿)))

(define (symbol->integer s) (char->integer (string-ref (symbol->string s) 0)))
(define (pick xs) (list-ref xs (random (length xs))))

(define glyphs
  (map
   integer->char
   (append*
    (for/list ([c (in-list codes)])
      (range (symbol->integer (first c)) (add1 (symbol->integer (second c))))))))

(define palette (vector-append (vector "\e[38;2;255;255;255m")
                               (for/vector ([n (in-range 245 29 -10)])
                                 (format "\e[38;2;0;~a;0m" n))
                               (make-vector 75 "\e[38;2;0;25;0m")))

(match-define (list (app (compose1 sub1 string->number) rows)
                    (app string->number cols))
  (string-split (with-output-to-string (thunk (system "stty size")))))

(define screen (for/vector ([_ (in-range (* rows cols))]) (pick glyphs)))
(define offsets (for/vector ([col cols]) (random (vector-length palette))))

(display "\e[?25l\e[48;5;232m") ; hide the cursor, set the background color

(define (main)
  (for ([iter (in-naturals)])
    (sleep 0.1)
    (display "\e[1;1H") ; reset cursor to top left
    (for ([i (in-range 30)]) (vector-set! screen (random (* rows cols)) (pick glyphs)))
    (for ([i (in-range rows)])
      (for ([j (in-range cols)])
        (display (vector-ref palette (modulo (+ (- i) iter (vector-ref offsets j))
                                             (vector-length palette))))
        (display (vector-ref screen (+ (* cols i) j))))
      (display "\n"))))

(with-handlers ([exn:break? (thunk*
                             ; reset ANSI codes, reshow cursor, clear screen
                             (display "\e[0m")
                             (display "\e[H\e[J\e[?25h"))])
  (main))

Raku

(formerly Perl 6)

Works with: Rakudo version 2018.11

Kind-of cheap and cheesy, but what the heck... Probably will only work in a POSIX compatible terminal. Runs until you hit ^C to exit.

The "lightning" effect is actually a bug, but I liked it so I kept it.

# clean up on exit, reset ANSI codes, scroll, re-show the cursor & clear screen
signal(SIGINT).tap: { print "\e[0m", "\n" xx 50, "\e[H\e[J\e[?25h"; exit(0) }

# a list of glyphs to use
my @codes = flat 'Α' .. 'Π', 'Ѐ' .. 'ѵ', 'Ҋ' .. 'ԯ', 'Ϣ' .. 'ϯ', 'ヲ'.. 'ン',
                 'Ⲁ' .. '⳩', '∀' .. '∗', '℀' .. '℺', '⨀' .. '⫿';

# palette of gradient ANSI foreground colors
my @palette = flat  "\e[38;2;255;255;255m", (255,24530).map({"\e[38;2;0;$_;0m"}),
              "\e[38;2;0;25;0m" xx 75;

my @screen; # buffer to hold glyphs
my @rotate; # palette rotation position buffer

my ($rows, $cols) = qx/stty size/.words; # get the terminal size
init($rows, $cols); # set up the screen buffer and palette offsets

my $size-check;

print "\e[?25l\e[48;5;232m"; # hide the cursor, set the background color

loop {
     if ++$size-check %% 20 {                         # periodically check for
         my ($r, $c) = qx/stty size/.words;           # resized terminal and
         init($r, $c) if $r != $rows or $c != $cols;  # re-initialize screen buffer
         $size-check = 0
     }
     print "\e[1;1H";                                 # set cursor to top left
     print join '', (^@screen).map: {
         @rotate[$_] = (@rotate[$_] + 1) % +@palette; # rotate the palettes
         flat @palette[@rotate[$_]], @screen[$_]      # and print foreground, glyph
     }
     @screen[(^@screen).pick] = @codes.roll for ^30;  # replace some random glyphs
}

sub init ($r, $c) {
    @screen = @codes.roll($r * $c);
    ($rows, $cols) = $r, $c;
    my @offset = (^@palette).pick xx $cols;
    for ^$rows -> $row {
        @rotate[$row * $cols ..^ $row * $cols + $cols] = @offset;
        # for no "lightning" effect, add   '1 + '  ↓ here: (1 + $_ % 3)
        @offset = (^@offset).map: {(@offset[$_] - ($_ % 3)) % +@palette};
    }
}
Sample output:

See matrix-digital-rain-perl6.png (offsite png image)

REXX

Digital rain note:   This REXX program favors the use of Latin letters   (both lower and uppercase)   letters over all others characters (glyphs) by a 25% factor.

/*REXX program creates/displays Matrix (the movie) digital rain; favors non-Latin chars.*/
signal on halt                                   /*allow the user to halt/stop this pgm.*/
parse arg pc seed .                              /*obtain optional arguments from the CL*/
if pc=='' | pc==","     then pc= 20              /*Not specified?  Then use the default.*/
if datatype(seed, 'W')  then call random ,,seed  /*Numeric?  Use seed for repeatability.*/
parse value  scrsize()  with  sd  sw  .          /*obtain the dimensions of the screen. */
if sd==0  then sd= 54;  sd= sd - 2 + 1           /*Not defined? Then use default; adjust*/
if sw==0  then sw= 80;  sw= sw - 1               /* "      "      "   "     "        "  */
lowC= c2d(' ')  +  1                             /*don't use any characters  ≤  a blank.*/
@.= ' '                                          /*PC  is the % new Matric rain streams.*/
cloud= copies(@., sw)                            /*the cloud, where matrix rain is born.*/
cls= 'CLS'                                       /*DOS command used to clear the screen.*/
                  do  forever;   call nimbus     /*define bottom of cloud  (the drops). */
                                 call rain       /*generate rain, display the raindrops.*/
                  end   /*j*/
halt:  exit                                      /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
rain:   do a=sd  by -1  for sd-1;   _= a-1;   @.a= @._;   end;      call fogger;    return
show:   cls;  @.1= cloud;    do r=1  for sd;  say strip(@.r, 'T');  end  /*r*/;     return
/*──────────────────────────────────────────────────────────────────────────────────────*/
nimbus: if random(, 100)<pc  then call mist      /*should this be a new rain stream ?   */
                             else call unmist    /*should any of the rain streams cease?*/
        return                                   /*note: this subroutine may pass──►MIST*/
        if random(, 100)<pc         then return  /*should this be a new rain stream ?   */
        ?= random(1, sw)                         /*pick a random rain cloud position.   */
        if substr(cloud,?,1)\==' '  then return  /*Is cloud position not a blank? Return*/
/*───── ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ────────────────────────────────────────────────────*/
mist:   ?= random(1, sw)                         /*obtain a random column in cloud.     */
        if substr(cloud,?,1)\==' '  then return  /*if this stream is active, return.    */
        if random(, 100)<pc         then return  /*should this be a new rain stream ?   */
        cloud= overlay(drop(), cloud, ?)         /*seed cloud with new matrix rain drop.*/
        return
/*──────────────────────────────────────────────────────────────────────────────────────*/
unmist: ?= random(1, sw)                         /*obtain a random column in cloud.     */
        if substr(cloud,?,1) ==' '  then return  /*if this stream is dry,  return.      */
        if random(, 100)>pc         then return  /*should this be a new dry stream ?    */
        cloud= overlay(' ', cloud, ?);   return  /*seed cloud with new matrix rain drop.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
drop:   Lat= random(1, 4)                        /*Now, chose a matrix rain stream char.*/
        tChr= 254;    if Lat==1  then tChr= 127  /*choose the  type of rain stream char.*/
        return d2c( random(lowC, tChr) )         /*Lat = 1?   This favors Latin letters.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
fogger: do f=1  for sw                           /*display a screen full of rain streams*/
        if substr(cloud, f, 1) \== ' '   then cloud= overlay( drop(), cloud, f)
        end   /*f*/;        call show;   return  /* [↑]  if raindrop, then change drop. */

Programming note:

The use of      random(, 100)     is
the same as   random(0, 100)     (inclusive).


This REXX program makes use of   SCRSIZE   REXX program (or BIF) which is used to determine the screen
width and depth of the terminal (console).   Some REXXes don't have this BIF.

The   SCRSIZE.REX   REXX program is included here   ───►   SCRSIZE.REX.


output   when using the default input:

(A screen snapshot shown at half size.)

              ░      O       3              k       ò         cº     Θ     &           F
              ~      Ö       ¡              )       Å         tπ     ÷     ç           ╛
              a      ±       █              q       L         P}     8     ╕           y
              Ü      d       |              Γ       1         P»     ≥     ╙           ù
              ╖      ¥       9              ╠       ▒         SÉ     k     ╟           }
              o      U       '              Æ       í         (N     E     C           0
              e      2       ╜              ─       ₧         bH     ï     Z           ╢
              o      å       -              S       2         ò┘     ║     P           ╖
              s      @       ê              ≈       ╝         ·v     F     4           û
              Æ      k       ┤              .ÿ      s         ╕@     b     U           ^
              9      ╩       «              ┐·      w         ╛-     e     U           =
              ≈      a       ┬              δu      ┬         ît     ╤     ╖           σ
              N      Ä       F              'N      @         ╒R     φ     O
              ô      @       Y              ÷x      X         ∩P     ¡     8
              9      ║       ╔              #■      ▌         d%     v     «
              ô      m       I              xm      :         Um     E     &
              ╚      »       r              >       ~         H@     /     ┤
              ⌂      k       E              1       ╜         Wc     J     s
              8      g       E              m       ƒ         Ωε     q     U
              V      ë       &              |       ï         ■~     ≥     X
              à      Ö       .              î       3         ₧=     ⌂     ±
              π      ì       è              n       ┬         ·▌     Z     W
              ¢      6       n              S       £         [x     £     {
              '      &       ?              ╖       )         jÑ     ╞     α
              î      ╔       x              F       ╨         ☺▌     7     ┘
              á      ë       j              *       -         rⁿ     ú     )
              '      S       ╥              ∙       E         v≡     o     ú
              .      <       V              ²       °         ]G     7     H
              p      8       ╣              o       ╤         FÇ     S      
              ┴      t       ö              ^       ╣         n╟     ╕     >
              *      æ       ò              ╡       4         d_     ├     «
              ╔      â       -              Q       P         un     ≥     M
              6      ²       ╢              ╔       E         ≤A     °     *
              /      :       q              L       R         cë     %     ≡
              3      x       $              ⌡       ¥         .Ω     E     :
              E      ┤       y              i       U         Z      ú     O
              ⌂      Σ                      .       ¥         }      Ä     °
              V      φ                              ≤         ╙      ╫     j
              }      à                      ?       3         '      ≤     .
              í      ▐                      ╞       =         ~      Ä     ç
              B      î                      ö                 (      ¬     ╘
              ┬      [                      6                 ═      ╡     ▌
              r      %                      f                 ╔      [     C
         _    {      è                      %                 ╫      ▒     Z
         1    ≈      ]                      !                 -      ╨     o        ¢
              ?      ÿ                      9                 Å      e     ß        σ
         µ    ■      α                      Z                 h      4     ⌠        4
         ñ    ╙      2                      8                 ;      2     ╣        !
         J    Ñ      :                      ~                 █      ª     ░        I
         ╥    í      ┴                      c                 !      U     ;        [
         Ω    Ç      ╫                      N                 W      ⌂     $        ╨
         ì    +      ₧                      _                 v      k     ò        X
         c    s      ¿                      3                 %      ½     F        ╠
         x    Γ      p                      ?                 £      S     ç        -
         g           /                      ╡                 :      é     æ        ^
         √           ⌐                      0                 Ü      .     9        Γ
         ⌡           ╕                      w                 0      î     ╖        l
         ║           ñ                      ½                 █      D     ≥        Θ
         6           F                      ù                 ;      O     %        à
         m           -                      4                 n      '     ╬        {
         ├           ╚                      K                 &      G     R        ╗

Rust

Github repository

Cargo.toml

[package]
name = "matrix-digital-rain"
version = "0.1.0"
edition = "2021"

[dependencies]
termion = "1.5.6"
rand = "0.8.5"

main.rs

#![warn(clippy::pedantic)] // make sure that clippy is even more annoying

use rand::prelude::{ThreadRng, SliceRandom};
use rand::{thread_rng, Rng};
use termion::{color::Rgb};
use termion::input::TermRead;
use termion::raw::IntoRawMode;
use std::sync::mpsc::{channel, TryRecvError};
use std::thread;
use std::{io::{Write, stdout, stdin}, iter::repeat, time::Duration};

/// Character pool to pick from
/// If your terminal is struggling with that choice, replace them by ordinary latin characters.
/// There's currently no nicer way to initialize constant array in Rust
const CHARS: [char; 322] = [
    'M', 'Ї', 'Љ', 'Њ', 'Ћ', 'Ќ', 'Ѝ', 'Ў', 'Џ', 'Б', 'Г', 'Д', 'Ж', 'И', 'Й', 'Л', 'П', 'Ф', 'Ц', 'Ч', 'Ш', 'Щ', 'Ъ',
    'Ы', 'Э', 'Ю', 'Я', 'в', 'д', 'ж', 'з', 'и', 'й', 'к', 'л', 'м', 'н', 'п', 'т', 'ф', 'ц', 'ч', 'ш', 'щ', 'ъ', 'ы',
    'ь', 'э', 'ю', 'я', 'ѐ', 'ё', 'ђ', 'ѓ', 'є', 'ї', 'љ', 'њ', 'ћ', 'ќ', 'ѝ', 'ў', 'џ', 'Ѣ', 'ѣ', 'ѧ', 'Ѯ', 'ѱ', 'Ѳ',
    'ѳ', 'ҋ', 'Ҍ', 'ҍ', 'Ҏ', 'ҏ', 'Ґ', 'ґ', 'Ғ', 'ғ', 'Ҕ', 'ҕ', 'Җ', 'җ', 'Ҙ', 'ҙ', 'Қ', 'қ', 'ҝ', 'ҟ', 'ҡ', 'Ң', 'ң',
    'Ҥ', 'ҥ', 'ҩ', 'Ҫ', 'ҫ', 'Ҭ', 'ҭ', 'Ұ', 'ұ', 'Ҳ', 'ҳ', 'ҵ', 'ҷ', 'ҹ', 'Һ', 'ҿ', 'Ӂ', 'ӂ', 'Ӄ', 'ӄ', 'ӆ', 'Ӈ', 'ӈ',
    'ӊ', 'Ӌ', 'ӌ', 'ӎ', 'Ӑ', 'ӑ', 'Ӓ', 'ӓ', 'Ӕ', 'ӕ', 'Ӗ', 'ӗ', 'Ә', 'ә', 'Ӛ', 'ӛ', 'Ӝ', 'ӝ', 'Ӟ', 'ӟ', 'ӡ', 'Ӣ', 'ӣ',
    'Ӥ', 'ӥ', 'Ӧ', 'ӧ', 'Ө', 'ө', 'Ӫ', 'ӫ', 'Ӭ', 'ӭ', 'Ӯ', 'ӯ', 'Ӱ', 'ӱ', 'Ӳ', 'ӳ', 'Ӵ', 'ӵ', 'Ӷ', 'ӷ', 'Ӹ', 'ӹ', 'Ӻ',
    'ӽ', 'ӿ', 'Ԁ', 'ԍ', 'ԏ', 'Ԑ', 'ԑ', 'ԓ', 'Ԛ', 'ԟ', 'Ԧ', 'ԧ', 'Ϥ', 'ϥ', 'ϫ', 'ϭ', 'ゥ', 'ェ', 'ォ', 'ャ', 'ュ', 'ョ', 'ッ',
    'ー', 'ア', 'イ', 'ウ', 'エ', 'オ', 'カ', 'キ', 'ク', 'ケ', 'コ', 'サ', 'シ', 'ス', 'セ', 'ソ', 'タ', 'チ', 'ツ', 'テ', 'ト', 'ナ', 'ニ',
    'ヌ', 'ネ', 'ノ', 'ハ', 'ヒ', 'フ', 'ヘ', 'ホ', 'マ', 'ミ', 'ム', 'メ', 'モ', 'ヤ', 'ユ', 'ヨ', 'ラ', 'リ', 'ル', 'レ', 'ロ', 'ワ', 'ン',
    'ⲁ', 'Ⲃ', 'ⲃ', 'Ⲅ', 'Γ', 'Δ', 'Θ', 'Λ', 'Ξ', 'Π', 'Ѐ', 'Ё', 'Ђ', 'Ѓ', 'Є', 'ⲉ', 'Ⲋ', 'ⲋ', 'Ⲍ', 'ⲍ', 'ⲏ', 'ⲑ', 'ⲓ',
    'ⲕ', 'ⲗ', 'ⲙ', 'ⲛ', 'Ⲝ', 'ⲝ', 'ⲡ', 'ⲧ', 'ⲩ', 'ⲫ', 'ⲭ', 'ⲯ', 'ⳁ', 'Ⳉ', 'ⳉ', 'ⳋ', 'ⳤ', '⳥', '⳦', '⳨', '⳩', '∀', '∁',
    '∂', '∃', '∄', '∅', '∆', '∇', '∈', '∉', '∊', '∋', '∌', '∍', '∎', '∏', '∐', '∑', '∓', 'ℇ', 'ℏ', '℥', 'Ⅎ', 'ℷ', '⩫',
    '⨀', '⨅', '⨆', '⨉', '⨍', '⨎', '⨏', '⨐', '⨑', '⨒', '⨓', '⨔', '⨕', '⨖', '⨗', '⨘', '⨙', '⨚', '⨛', '⨜', '⨝', '⨿', '⩪',
    ];

/// convert a brightness value to a green-ish gradient color
fn color(brightness: u8) -> Rgb {
    let v = f32::from(brightness) / 255.0;
    let r = v.powi(7);
    let g = v.powi(1);
    let b = v.powi(4);
    // r, g, b will be in 0.0..=1.0 so there's no risk of exceeding the u8's range
    #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
    Rgb ((r * 255.0).round() as u8, (g * 255.0).round() as u8, (b * 255.0).round() as u8)
}

/// A single character on the screen with its current brightness
#[derive(Clone, Copy)]
struct Symbol {
    char: char,
    brightness: u8,
}

/// Start with a black space by default
impl Default for Symbol {
    fn default() -> Self {
        Self { char: ' ', brightness: 0 }
    }
}

impl Symbol {
    /// output the colored symbol at the current cursor position
    fn print<W: Write>(self, out: &mut W) {
        write!(out, "{}{}", termion::color::Fg(color(self.brightness)), self.char).unwrap();
    }

    /// reduce the brightness of the symbol by a certain amount and make sure the value doesn't underrun
    fn darken(&mut self) {
        self.brightness = self.brightness.saturating_sub(10);
    }

    /// replace the character for this symbol and bring it to full brightness
    fn set(&mut self, char: char) {
        self.char = char;
        self.brightness = 255;
    }
}

/// a single column of symbols
#[derive(Clone)]
struct Column {
    symbols: Vec<Symbol>,
}

impl Column {
    /// create a new column with a given height
    fn new(height: usize) -> Self {
        Self {
            symbols: vec![Symbol::default(); height],
        }
    }

    /// print out a single colored symbol of this column
    fn print_symbol<W: Write>(&self, out: &mut W, row: usize) {
        self.symbols[row].print(out);
    }

    /// reduce the brightness of the entire column
    fn darken(&mut self) {
        self.symbols.iter_mut().for_each(Symbol::darken);
    }

    fn set(&mut self, row: usize, char: char) {
        self.symbols[row].set(char);
    }
}

/// Current position of a _falling symbol_
struct Droplet {
    /// For the start of the animation we want to be able to place the symbol _above_ the screen,
    /// that's we need negative row values as well.
    row: isize,
    col: usize,
}

impl Droplet {
    /// create a new Droplet at a random location somewhere above the actual screen
    fn new_random(rng: &mut ThreadRng, width: usize, height: usize) -> Self {
        // the height of the terminal is expected lie within a sane range of this type
        #[allow(clippy::cast_possible_wrap)]
        Self {
            row: -(rng.gen_range(0..height) as isize),
            col: rng.gen_range(0..width),
        }
    }

    /// move the droplet down by one row
    /// if it hits the bottom row, move it back up to a random column
    fn update(&mut self, width: usize, height: usize) {
        self.row += 1;
        // the height of the terminal is expected lie within a sane range of this type
        #[allow(clippy::cast_possible_wrap)]
        if self.row >= height as isize {
            let mut rng = thread_rng();
            self.col = rng.gen_range(0..width);
            self.row = 0;
        }
    }
}

/// The entire screen filled with colored symbols
struct Screen {
    width: usize,
    height: usize,
    columns: Vec<Column>,
    droplets: Vec<Droplet>,
}

impl Screen {

    /// create a new empty screen with the given dimensions
    fn new(width: usize, height: usize) -> Self {
        let mut rng = thread_rng();
        Self {
            width,
            height,
            columns: repeat(Column::new(height)).take(width).collect(),
            droplets: (0..width).map(|_| Droplet::new_random(&mut rng, width, height)).collect(),
        }
    }

    /// print the entire screen to the terminal
    fn print<W: Write>(&self, out: &mut W) {
        for row in 0..self.height {
            for column in &self.columns {
                column.print_symbol(out, row);
            }
            write!(out, "\r\n").unwrap();
        }
    }

    // make all droplets fall down by one row
    fn update_droplets(&mut self) {
        let mut rng = thread_rng();
        for droplet in &mut self.droplets {
            droplet.update(self.width, self.height);
            if let Ok(row) = droplet.row.try_into() {
                let ch = CHARS.choose(&mut rng).copied().unwrap_or(' ');
                self.columns[droplet.col].set(row, ch);
            }
        }
    }

    // reduce the brightness of all symbols in this screen
    fn darken(&mut self) {
        self.columns.iter_mut().for_each(Column::darken);
    }

}

fn main() {
    // create the screen with the terminal's dimensions (omit the last row to prevent auto-scrolling)
    let (width, height) = termion::terminal_size().unwrap();
    let mut screen = Screen::new(width as usize, height as usize - 1);

    // create a channel which allows to send stuff between thread boundaries
    let (tx, rx) = channel();
    
    // spawn a new thread which will blockingly wait for a key to be pressed
    thread::spawn(move || {
        stdin().keys().next();
        // send something down the channel to notify the main thread that a key has been pressed
        tx.send(()).expect("Could not send signal on channel.");
    });

    // get write access to the terminal
    let mut stdout = stdout().into_raw_mode().unwrap();

    // clear the screen and hide the cursor
    write!(stdout, "{}{}", termion::clear::All, termion::cursor::Hide).unwrap();

    // continue while no key has been pressed (i.e. the notification channel is empty)
    while rx.try_recv() == Err(TryRecvError::Empty) {
        // move cursor to the top left and set background color to black
        write!(stdout, "{}{}", termion::cursor::Goto(1, 1), termion::color::Bg(termion::color::Rgb(0, 0, 0))).unwrap();

        // screen update
        screen.print(&mut stdout);
        screen.darken();
        screen.update_droplets();
        // make sure the terminal updates _now_
        stdout.flush().unwrap();

        // slow down animation
        std::thread::sleep(Duration::from_millis(50));
    }

    // reset Terminal back to normal
    write!(stdout, "{}", termion::style::Reset).unwrap();
    write!(stdout, "{}", termion::clear::All).unwrap();
    write!(stdout, "{}", termion::cursor::Goto(1, 1)).unwrap();
    write!(stdout, "{}", termion::cursor::Show).unwrap();
}

Wren

Translation of: Yabasic
Library: DOME

The memory.ttf file is included with the DOME 'fonts' example and can be downloaded from here.

import "dome" for Window
import "graphics" for Canvas, Color, Font
import "random" for Random

var Rand = Random.new()

class MatrixDigitalRain {
    construct new(width, height) {
        Window.resize(width, height)
        Canvas.resize(width, height)
        Window.title = "Matrix digital rain"
        Font.load("Mem12", "memory.ttf", 24)
        Canvas.font = "Mem12"
    }

    letter(x, y, r, g, b) {
        if (y < 0 || y >= _my) return
        var col = Color.rgb(r, g, b)
        var c = String.fromByte(_scr[x][y])
        Canvas.print(c, x * 12.8 , y * 12.8 , col)
    }

    init() {
        _mx = 50
        _my = 42
        _scr = List.filled(_mx, null)
        for (x in 0..._mx) {
            _scr[x] = List.filled(_my, 0)
            for (y in 0..._my) _scr[x][y] = Rand.int(33, 128)
        }
        _ms = 50
        _sx = List.filled(_ms, 0)
        _sy = List.filled(_ms, 0)
    }

    update() {
        for (a in 0..._ms) {
            _sx[a] = Rand.int(_mx)
            _sy[a] = Rand.int(_my)
        }
    }

    draw(alpha) {
        for (s in 0..._ms) {
            var x = _sx[s]
            var y = _sy[s]
            letter(x, y, 0, 255, 0)
            y = y - 1
            letter(x, y, 0, 200, 0)
            y = y - 1
            letter(x, y, 0, 150, 0)
            y = y - 1
            if (y*12.8 + 3 < 0) y = 0
            var c = Color.rgb(0, 0, 0)
            Canvas.rectfill(x*12.8, y*12.8 + 3, 13, 14, c)
            letter(x, y, 0, 70, 0)
            y = y - 24
            if (y*12.8 + 3 < 0) y = 0
            Canvas.rectfill(x*12.8, y*12.8  + 3, 13, 14, c)
        }
        for (s in 0..._ms) {
            if (Rand.int(1, 6) == 1) _sy[s] = _sy[s] + 1
            if (_sy[s] > _my + 25) {
                _sy[s] = 0
                _sx[s] = Rand.int(_mx)
            }
        }               
    }
}

var Game = MatrixDigitalRain.new(640, 550)

Yabasic

open window 640,512,"swiss12"
backcolor 0,0,0
clear window
mx=50
my=42
dim scr(mx,my)
for y=0 to my
    for x=0 to mx
        scr(x,y)=int(ran(96)+33)
    next x
next y
ms=50
dim sx(ms)
dim sy(ms)
for a=1 to ms
    sx(a)=int(ran(mx))
    sy(a)=int(ran(my))
next a
do
    for s=1 to ms
        x=sx(s)
        y=sy(s)
        
        letter(0,255,0)
        y=y-1
        
        letter(0,200,0)
        y=y-1
        
        letter(0,150,0)
        y=y-1
        
        color 0,0,0
        fill rect x*12.8-1,y*12.8+4 to x*12.8+12,y*12.8-10
        letter(0,70,0)
        y=y-24
        
        color 0,0,0
        fill rect x*12.8-1,y*12.8+4 to x*12.8+12,y*12.8-10
    next s
    for s=1 to ms
        if int(ran(5)+1)=1 sy(s)=sy(s)+1
        if sy(s)>my+25 then
            sy(s)=0
            sx(s)=int(ran(mx))
        end if
    next s
loop

sub letter(r,g,b)
    if y<0 or y>my return
    c=scr(x,y)
    color r,g,b
    text x*12.8,y*12.8,chr$(c)
end sub

zkl

Translation of: Raku
var [const] codes=Walker.chain(  // a bunch of UTF non ascii chars
         [0x0391..0x03a0], [0x03a3..0x0475], [0x0400..0x0475],
         [0x048a..0x052f], [0x03e2..0x03ef], [0x2c80..0x2ce9],
         [0x2200..0x2217], [0x2100..0x213a], [0x2a00..0x2aff])
	 .apply(fcn(utf){ utf.toString(-8) }),  // jeez this is lame
    codeSz=codes.len(),	// 970
    c=L("\e[38;2;255;255;255m",[255..30,-15].apply("\e[38;2;0;%d;0m".fmt),
        (250).pump(List,T(Void,"\e[38;2;0;25;0m"))).flatten(),
    csz=c.len(); // 267, c is ANSI escape code fg colors: 38;2;<r;g;b>m
 
// query the ANSI terminal
rows,cols := System.popen("stty size","r").readln().split().apply("toInt");

o,s,fg := buildScreen(rows,cols);
ssz:=s.len();

print("\e[?25l\e[48;5;232m");  // hide the cursor, set background color to dark
while(1){		       // ignore screen resizes
   print("\e[1;1H");	       // move cursor to 1,1
   foreach n in (ssz){	       // print a screen full
      print( c[fg[n]], s[n] ); // forground color, character
      fg[n]=(fg[n] + 1)%csz;   // fade to black
   }
   do(100){ s[(0).random(ssz)]=codes[(0).random(codeSz)] }  // some new chars
   Atomic.sleep(0.1);	       // frame rate for my system, up to 200x41 terminal
}

fcn buildScreen(rows,cols){    // build a row major array as list
   // s --> screen full of characters
   s:=(rows*cols).pump(List(), fcn{ codes[(0).random(codeSz)]});
   // array fb-->( fg color, fg ..) where fg is an ANSI term 48;5;<n>m color
   fg:=List.createLong(s.len(),0);
   o:=csz.pump(List()).shuffle()[0,cols];  // cols random #s
   foreach row in (rows){		   // set fg indices
      foreach col in (cols){ fg[row*cols + col] = o[col] }
      o=o.apply(fcn(n){ n-=1; if(n<0) n=csz-1; n%csz });  // fade out
   }
   return(o,s,fg);
}

Offsite Image: Matrix rain dance

ZX Spectrum Basic

Appallingly slow (full speed on an emulator strongly recommended), but it works.

Authentic Matrix code includes reversed Latin characters and half-width Japanese. The Spectrum doesn't have anything like the space in the glyphs to support legible Japanese, but this program does use a machine code routine to generate a reversed Spectrum character set - and an upside down one and an upside down and reversed one, for good measure. (This could be duplicated in Basic but the program is slow enough as it is - ZX Spectrum Basic has no bitwise operations.) If you don't want to use the machine code (because this is a Basic demonstration, after all), or the alternate character sets, delete lines 30 and 4000; this will leave you with standard upright characters.

The left-right flip portion of the machine code routine is by John Metcalf, borrowed from his blog. (He has also posted a routine for the Matrix rain in Spectrum Z80 Assembly; his method, filling the screen with characters first and then applying the attributes, was one I had independently considered for this routine, but I didn't feel it resulted in enough character change.)

The PEEKs and POKEs throughout the routine are used for attribute handling. PEEK (22528+32*x+y) is the same thing as ATTR (x,y).

The next step for this routine would be a way to randomise the length of the character trails (currently fixed at 12).

10 CLEAR 61999
20 BORDER 0: POKE 23624,4: POKE 23693,0: CLS: REM easier than "bright 0: flash 0: ink 0: paper 0"
30 PRINT INK 4; FLASH 1;"Initialising": GO SUB 9000: LET m=USR 62000: CLS: REM set up and run machine code; USR is the call function
40 DIM s(32,2): REM current top and bottom of character sequence for each of the 32 spaces across the screen

50 FOR x=1 TO 32: REM main loop
60 IF s(x,1)=0 AND RND>.95 THEN LET s(x,1)=1: LET s(x,2)=2: GO SUB 4000: GO SUB 3000: GO TO 80: REM start a new column; decrease the .95 modifier for a busier - but slower - screen
70 IF s(x,2)>0 THEN GO SUB 1000
80 NEXT x
90 FOR l=1 TO 10: REM matrix code switches existing glyphs occasionally
100 LET x=INT (RND*22): LET y=INT (RND*32)
110 IF PEEK (22528+32*x+y)=0 THEN GO TO 140: REM no point updating a blank space
120 GO SUB 4000
130 PRINT AT x,y; INK 8; BRIGHT 8;CHR$ (33+RND*95): REM ink 8 and bright 8 tells it to keep the cell's existing ink and bright values
140 NEXT l
150 GO TO 50

999 REM continue an existing column
1000 LET s(x,2)=s(x,2)+1
1010 IF s(x,2)<21 THEN GO SUB 3000
1020 IF s(x,2)>12 THEN LET s(x,1)=s(x,1)+1
1030 LET k=2
1040 GO SUB 2000
1050 LET k=6
1060 GO SUB 2000
1070 LET k=12
1080 GO SUB 2000
1090 IF s(x,1)=22 THEN LET s(x,1)=0: LET s(x,2)=0
1100 RETURN 

1999 REM update colour
2000 LET a=22527+x+32*(s(x,2)-k)
2010 LET c=PEEK a
2020 IF c=4 THEN POKE a,0
2030 IF c=68 THEN POKE a,4
2040 IF c=71 THEN POKE a,68: REM this poke could be done with 'print at s(x,2)-k-1,x-1; ink 4; bright 1; over 1; " " ' but poking is FAR easier, especially considering the above pokes would be similar
2050 RETURN 

2999 REM new character at bottom of column
3000 PRINT AT s(x,2)-1,x-1; INK 7; BRIGHT 1;CHR$ (33+RND*95)
3010 RETURN 

3999 REM select character set
4000 POKE 23607,242+3*INT (RND*4): REM the spectrum character set is pointed to by the two-byte system value CHARS at 23606 and 23607, so repoking this selects a new character set - the machine code below has created four copies of the character set at suitable locations
4010 RETURN 

8999 REM machine code routine to create multiple character sets
9000 RESTORE 9800
9010 LET h$="0123456789ABCDEF"
9020 LET o=62000
9030 IF PEEK o=33 AND PEEK 62121=201 THEN RETURN: REM saves storing it all again if the machine code is already there
9040 READ a$
9050 IF a$="eof" THEN RETURN 
9060 FOR x=1 TO 8
9070 LET n=0
9080 LET s=(x*2)-1
9090 LET t=s+1
9100 FOR m=1 TO 16
9110 IF h$(m)=a$(s) THEN LET n=n+16*(m-1)
9120 IF h$(m)=a$(t) THEN LET n=n+m-1
9130 NEXT m
9140 POKE o,n
9150 LET o=o+1
9160 NEXT x
9170 GO TO 9040

9800 DATA "21003D1100F30100"
9810 DATA "03EDB02100F31100"
9820 DATA "F6010009EDB01100"
9830 DATA "F901FF051A6F0707"
9840 DATA "ADE6AAAD6F070707"
9850 DATA "CB0DADE666AD1213"
9860 DATA "0B78B120E721FFF5"
9870 DATA "010000E5CD8BF2E1"
9880 DATA "E5CD8BF2E1E5CD8B"
9890 DATA "F2E1CD8BF2232323"
9900 DATA "23AF470C79FEC0C2"
9910 DATA "6BF2C9E5D1043E09"
9920 DATA "90835F8A93577885"
9930 DATA "6F8C95671AE521AA"
9940 DATA "F277E17E123AAAF2"
9950 DATA "77C9000000000000"
9960 DATA "eof"

9999 POKE 23606,0: POKE 23607,60: INK 4: REM reset to default character set and colour if you get lost

Offsite Image: Spectrum rain at imgur