[![saythanks](https://img.shields.io/badge/say-thanks-ff69b4.svg)](https://saythanks.io/to/irmen) [![Build Status](https://travis-ci.org/irmen/prog8.svg?branch=master)](https://travis-ci.org/irmen/prog8) [![Documentation](https://readthedocs.org/projects/prog8/badge/?version=latest)](https://prog8.readthedocs.io/) Prog8 - Structured Programming Language for 8-bit 6502/65c02 microprocessors ============================================================================ *Written by Irmen de Jong (irmen@razorvine.net)* *Software license: GNU GPL 3.0, see file LICENSE* This is a structured programming language for the 8-bit 6502/6510/65c02 microprocessor from the late 1970's and 1980's as used in many home computers from that era. It is a medium to low level programming language, which aims to provide many conveniences over raw assembly code (even when using a macro assembler). Documentation ------------- Full documentation (syntax reference, how to use the language and the compiler, etc.) can be found at: https://prog8.readthedocs.io/ What does Prog8 provide? ------------------------ - big reduction of source code length over raw assembly - modularity, symbol scoping, subroutines - various data types other than just bytes (16-bit words, floats, strings) - automatic variable allocations, automatic string and array variables and string sharing - subroutines with an input- and output parameter signature - no stack frame allocations because parameters and local variables are automatically allocated statically - constant folding in expressions and other high-level program optimizations - conditional branches - floating point operations (requires the C64 Basic ROM routines for this) - 'when' statement to provide a concise jump table alternative to if/elseif chains - structs to group together sets of variables and manipulate them at once - many built-in functions such as ``sin``, ``cos``, ``rnd``, ``abs``, ``min``, ``max``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``swap``, ``sort`` and ``reverse`` - various powerful built-in libraries to do I/O, number conversions, graphics and more - convenience abstractions for low level aspects such as ZeroPage handling, program startup, explicit memory addresses - fast execution speed due to compilation to native assembly code - inline assembly allows you to have full control when every cycle or byte matters - supports the sixteen 'virtual' 16-bit registers R0 .. R15 from the Commander X16, and provides them also on the C64. *Rapid edit-compile-run-debug cycle:* - use a modern PC to do the work on, use nice editors and enjoy quick compilation times - can automatically run the program in the Vice emulator after succesful compilation - breakpoints, that let the Vice emulator drop into the monitor if execution hits them - source code labels automatically loaded in Vice emulator so it can show them in disassembly *Two supported compiler targets* (contributions to improve these or to add support for other machines are welcome!): - "c64": Commodore-64 (6510 CPU = almost a 6502) - "cx16": [CommanderX16](https://www.commanderx16.com) (65c02 CPU) - If you only use standard kernal and prog8 library routines, it is possible to compile the *exact same program* for both machines (just change the compiler target flag)! Additional required tools ------------------------- [64tass](https://sourceforge.net/projects/tass64/) - cross assembler. Install this on your shell path. A recent .exe version of this tool for Windows can be obtained from my [clone](https://github.com/irmen/64tass/releases) of this project. For other platforms it is very easy to compile it yourself (make ; make install). A **Java runtime (jre or jdk), version 11 or newer** is required to run a prepackaged version of the compiler. If you want to build it from source, you'll need a Java SDK + Kotlin 1.3.x SDK (or for instance, IntelliJ IDEA with the Kotlin plugin). It's handy to have an emulator (or a real machine perhaps!) to run the programs on. The compiler assumes the presence of the [Vice emulator](http://vice-emu.sourceforge.net/) for the C64 target, and the [x16emu emulator](https://github.com/commanderx16/x16-emulator) for the CommanderX16 target. Example code ------------ This code calculates prime numbers using the Sieve of Eratosthenes algorithm:: %import textio %zeropage basicsafe main { ubyte[256] sieve ubyte candidate_prime = 2 ; is increased in the loop sub start() { sys.memset(sieve, 256, false) ; clear the sieve txt.print("prime numbers up to 255:\n\n") ubyte amount=0 repeat { ubyte prime = find_next_prime() if prime==0 break txt.print_ub(prime) txt.print(", ") amount++ } txt.nl() txt.print("number of primes (expected 54): ") txt.print_ub(amount) txt.nl() } sub find_next_prime() -> ubyte { while sieve[candidate_prime] { candidate_prime++ if candidate_prime==0 return 0 ; we wrapped; no more primes } ; found next one, mark the multiples and return it. sieve[candidate_prime] = true uword multiple = candidate_prime while multiple < len(sieve) { sieve[lsb(multiple)] = true multiple += candidate_prime } return candidate_prime } } when compiled an ran on a C-64 you'll get: ![c64 screen](docs/source/_static/primes_example.png) One of the included examples (wizzine.p8) animates a bunch of sprite balloons and looks like this: ![wizzine screen](docs/source/_static/wizzine.png) Another example (cube3d-sprites.p8) draws the vertices of a rotating 3d cube: ![cube3d screen](docs/source/_static/cube3d.png) If you want to play a video game, a fully working Tetris clone is included in the examples: ![tehtriz_screen](docs/source/_static/tehtriz.png) There are a couple of examples specially made for the CommanderX16 compiler target. For instance here's a well known space ship animated in 3D with hidden line removal, in the CommanderX16 emulator: ![cobra3d](docs/source/_static/cobra3d.png)