Welcome! This hands‑on guide is for absolute beginners. You’ll learn the basics by writing and running tiny programs inside Retro Rocket. No prior programming experience needed.

Remarks: How this works • Open the built‑in editor with edit <name>• Save with Ctrl+S. • Run from the shell by typing its name you saved it as.\; • Press CTRL+ESC while a program is running to stop it.

We’ll start simple and build up.

1) Your first program: printing text

Open the editor:

edit

Type this and save (Ctrl+S) with the name: hello

PRINT "Hello, Retro Rocket!"

Leave the editor, then run it:

hello

You should see the message appear. That’s your first program!

Notes

PRINT writes text to the screen.
Quotes surround literal text (called a string).

2) Variables and simple maths

Open a new file:

edit

Type and save (Ctrl+S) as mathsdemo:

A = 2
B = 3
SUM = A + B
PRINT "2 + 3 = "; SUM

Run it:

mathsdemo

What’s happening

You create variables with =. Names like A, B, SUM hold numbers.
PRINT ...; ... prints items on one line (the semicolon avoids an automatic newline between parts).

Three value types you’ll meet

Integers (whole numbers) - default: AGE = 12
Reals (decimals) - suffix #: PI# = 3.14159
Strings (text) - suffix $: NAME$ = "Ada"

Use the right suffix when you want a real or string. Integers have no suffix.

3) Getting input and using strings

Open:

edit

Type and save (Ctrl+S) as hello_you:

PRINT "What is your name?"
INPUT NAME$
PRINT "Nice to meet you, "; NAME$

Run:

hello_you

What’s happening

INPUT waits for you to type a line and press Enter, then stores it in a variable.
String variables end with $.

4) Making decisions (IF / ELSE)

Open:

edit

Type and save (Ctrl+S) as agegate:

PRINT "How old are you?"
INPUT AGE
IF AGE < 13 THEN
  PRINT "Hi there!"
ELSE
  PRINT "Welcome."
ENDIF

Run it and try different ages.\ IF ... THEN chooses a path; ELSE is optional; ENDIF closes the block.

5) Repeating work (FOR and WHILE)

A counting loop

FOR I = 1 TO 5
  PRINT "Number "; I
NEXT

A condition‑driven loop

N = 5
WHILE N > 0
  PRINT N
  N = N - 1
ENDWHILE
PRINT "Lift‑off!"

6) Breaking code into procedures and functions

Procedures are reusable blocks that don’t return a value. Functions return a value.

Procedure example

DEF PROCGreet(NAME$)
  PRINT "Hello, "; NAME$
ENDPROC
 
PROCGreet("Ada")
PROCGreet("Grace")

Function example

DEF FNAdd(A, B)
 = A + B
 
PRINT "2 + 3 = "; FNAdd(2, 3)

Notes

Call a procedure with PROCName(...).
Call a function with FNName(...). The line starting with = returns the value.

7) A tiny project: Guess the number

edit

Type and save (Ctrl+S) as guess:

PRINT "I am thinking of a number between 1 and 10."
SECRET = 7
PRINT "Your guess?"
INPUT GUESS
IF GUESS = SECRET THEN
  PRINT "Correct!"
ELSE
  PRINT "Not this time."
ENDIF

Run with guess. Improve it by looping until correct, counting attempts, or giving hints (IF GUESS < SECRET THEN ...).

8) Tips and troubleshooting

Stopping a program: press ESC. (Advanced: you can catch this with ON ERROR PROC ... and check ERR$.)
Saving: remember Ctrl+S in the editor.
Printing tricks:
- Use a comma to tab‑separate: PRINT A, B, C
- Use semicolon to join on one line: PRINT "X="; X; " Y="; Y

9) Where to go next

Try combining INPUT, IF, and loops to make simple text games.
Learn about arrays and sprites when you’re comfortable with the basics.
Browse the separate “BASIC.md” internals doc if you’re curious how the interpreter works under the hood.

You’ve got this-keep experimenting!