BASIC-RoBots /


What is BASIC-RoBots ?

BASIC-RoBots is a real-time strategy game about programming robots to colonize a planet.

How to launch this game ?

BASIC-RoBots depends on Python2, PyGame and PyOpenGL.

For Debian/Ubuntu Linux:

$ sudo apt-get install python2.6 python-pygame python-opengl
$ cd /path/to/basic-robots/
$ make

How to control robots ?

The robots can only be controlled with command line. Press [Ctrl+N], or [ENTER] key when you select a robot, to open a terminal on the selected robot.

There are 2 types of commands:

  • Internal commands : Internal controls of the operating system (Ex : cd, mkdir, let, edit, ...)
  • External commands : commands to interact with the robot and the outside world (Ex : forward, rotleft, build, ...)

Type intcmd to show the internal commands of the robots and extcmd to show external commands.


Move forward and rotate the robot

> forward
forward-> 1
> rotleft
rotleft-> 1

Build a Tipper with a Mothership

> help build
> robots
Id  Name
0   Woodcutter
1   Tipper
2   Thermal Power Station
robots-> 0
> let A 1
> build

Cut a tree with a Woodcutter

> cuttree
> inv
Id  Item      Qty
1   Sapling   2
0   Wood      8

Capacity: 100000 g
Weight: 80004 g
Free: 19996 g (19 %)

Robots features

File system

Each robot has its own file system. So, feel free to create folders and files in the robots with the commands mkdir, touch, edit, ...



A robot owns 4 registers of 1 byte each that can be written with the command let (usable in BASIC-script and in terminal) :

  • A
  • B
  • C
  • D

Read only

The read-only registers can only be used in expressions. It's forbidden to assign value to this registers.

  • O : Overflow flag. Gets the value 1 if an arithmetic overflow has occurred in the last expression, 0 otherwise.
  • SH : Shield value of the robot. Not use in this version
  • EN : Energy value of the robot.
  • X : first component (in Cartesian coordinates) of the position of the robot
  • Y : second component (in Cartesian coordinates) of the position of the robot
  • K : contains keyboard inputs


A robot also owns a LIFO memory, useful for storing data temporarily. You can see the content of the stack with the command stack. See the BASIC commands PUSH and POP for details on usage.

BASIC Programming Language

The robots can be programmed with a specific language based on BASIC. You can edit a program with the command edit FILE, run it with run FILE and debug it with debug FILE.


Input and Output

  • PRINT : displays a message on the terminal
  • READ : asks the user to enter the value of a register
  • LET : assigns a value (which may be the result of an expression) to a register
  • CALL : call an external command and assigns the return to a register
  • PUSH : push the value of a register in the stack
  • POP : pop the value from the top of the stack to a register

Program flow control

  • IF ... THEN ... ELSE : used to perfoms comparaisons or make decisions
  • WHILE ... ENDWHILE : repeat a section of code while the specified condition is true
  • LABEL : labels current line
  • GOTO : jumps to a labelled line in the program
  • GOTOSUB : temporarily jumps to a labelled line, returning to the following line after encountering the RETURN command


  • REM : holds a programmer's comment
  • INCLUDE : includes the content of an other file to the current program


Loop example

REM *** Moves the robot 5 squares forward ***
REM Store the value of the register A

REM Set the value of A to 4

REM Repeat while the value of A is positive

   REM Decrement the value of A
   LET A A-1

   REM Call the external command "forward"
   CALL forward


REM Get the stored value of A

Use the standard library

REM Move the robot to the entered coordinates
REM Include the file lib/move
INCLUDE lib/move


PRINT Current position :
PRINT ( $X , $Y )
PRINT A : X - B : Y

REM Ask the user to enter coordinates

REM Call subroutine defined in lib/move
GOTOSUB move_to