ZX Spectrum Basic

'''ZX Spectrum Basic''' is the BASIC built into the ROM of the ZX Spectrum Computer.

Features

• Language is interpreted (but third party compiler is available).
• Line numbers are required
• Line numbers must be no longer than four digits
• No named locations
• Some Terminal Control capabilities
• Supports colour
• Support for direct display graphics
• Support for sound via the speaker
• No support for scoped variables
• No support for structured variables
• No command line parameters
• No support for environment
• Supports output tho the line printer via the lprint command
• No direct support for error handling, but error handling can be achieved using assembly language by changing the error handler address
• Support for streams when using Interface 1, but no support for freefile
• Can read keystrokes using INKEY$
• No support for multiple line IF conditionals
• No conditional compilation directives
• no hashbang mechanism
• Variables have to be defined before use
• The GO TO command has a space in the middle
• VAL function interprets expressions
• INPUT function can interpret expressions (unless LINE INPUT is used)

Tasks

• 24 game
• A+B
• ABC Problem
• Abundant, deficient and perfect number classifications
• Ackermann function
• Align columns
• Aliquot sequence classifications
• Almost prime
• Amicable pairs
• Animate a pendulum
• Animation
• Anonymous recursion
• Apply a callback to an array
• Arithmetic evaluation
• Arithmetic-geometric mean
• Arithmetic/Complex
• Arithmetic/Integer
• Array concatenation
• Arrays
• Audio frequency generator
• Balanced brackets
• Barnsley fern
• Benford's law
• Best shuffle
• Binary digits
• Binary search
• Binary strings
• Box the compass
• Brownian tree
• Bulls and cows
• Caesar cipher
• Calculating the value of e
• Call a function
• Carmichael 3 strong pseudoprimes
• Case-sensitivity of identifiers
• Casting out nines
• Catalan numbers
• Catalan numbers/Pascal's triangle
• Catamorphism
• Chaos game
• Character codes
• Chinese remainder theorem
• Cholesky decomposition
• Circles of given radius through two points
• Closest-pair problem
• Color of a screen pixel
• Colour bars/Display
• Combinations with repetitions
• Comma quibbling
• Compare a list of strings
• Constrained random points on a circle
• Continued fraction
• Convert seconds to compound duration
• Copy a string
• Count in factors
• Count in octal
• Count occurrences of a substring
• Count the coins
• Create a file
• Create a file on magnetic tape
• Create a two-dimensional array at runtime
• Day of the week
• Delete a file
• Digital root
• Dinesman's multiple-dwelling problem
• Documentation
• Dot product
• Dragon curve
• Draw a clock
• Draw a cuboid
• Draw a pixel
• Draw a sphere
• Dutch national flag problem
• Empty program
• Empty string
• Entropy
• Equilibrium index
• Ethiopian multiplication
• Euler method
• Euler's sum of powers conjecture
• Evaluate binomial coefficients
• Even or odd
• Execute Brainfuck
• Execute a system command
• Exponentiation operator
• Extend your language
• Factorial
• Factors of an integer
• Fibonacci sequence
• Fibonacci word
• Filter
• Find limit of recursion
• Find the missing permutation
• FizzBuzz
• Flatten a list
• Floyd's triangle
• Forest fire
• Formatted numeric output
• Forward difference
• Fractal tree
• Function composition
• Function definition
• General FizzBuzz
• Generate lower case ASCII alphabet
• Greatest element of a list
• Greatest subsequential sum
• Greyscale bars/Display
• Guess the number
• Guess the number/With feedback
• Guess the number/With feedback (player)
• Hamming numbers
• Happy numbers
• Harshad or Niven series
• Haversine formula
• Hello world!
• Hello world/Newbie
• Hello world/Newline omission
• Hello world/Standard error
• Hello world/Text
• Higher-order functions
• Hofstadter Q sequence
• Hofstadter-Conway $10,000 sequence
• Horizontal sundial calculations
• IBAN
• Identity matrix
• Idiomatically determine all the lowercase and uppercase letters
• Include a file
• Infinity
• Integer comparison
• Introspection
• Iterated digits squaring
• Jaro distance
• Jensen's Device
• Josephus problem
• Julia set
• Keyboard input/Flush the keyboard buffer
• Keyboard input/Keypress check
• Keyboard input/Obtain a Y or N response
• Leap year
• Loop over multiple arrays simultaneously
• Loops/Downward for
• Loops/For
• Loops/For with a specified step
• Loops/Nested
• Luhn test of credit card numbers
• Memory allocation
• Modulinos
• Musical scale
• N'th
• Narcissistic decimal number
• Pascal's triangle
• Primality by trial division
• Pythagorean triples
• Random number generator (included)
• Random numbers
• Read a file line by line
• Rename a file
• Rot-13
• Scope/Function names and labels
• Sieve of Eratosthenes
• Snake
• Sorting Algorithms/Circle Sort
• Sorting algorithms/Bubble sort
• Sorting algorithms/Cocktail sort
• Speech synthesis
• Spinning rod animation/Text
• Split a character string based on change of character
• Start from a main routine
• String concatenation
• String length
• Subleq
• Substring
• Substring/Top and tail
• Taxicab numbers
• Temperature conversion
• Terminal control/Cursor movement
• Terminal control/Unicode output
• Truncate a file
• Unicode strings
• Variable size/Set
• Write float arrays to a text file
• Yin and yang