Prog8 - Structured Programming Language for 8-bit 6502/6510 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 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): - reduction of source code length - easier program understanding (because it's higher level, and more terse) - option to automatically run the compiled program in the Vice emulator - modularity, symbol scoping, subroutines - subroutines have enforced input- and output parameter definitions - various data types other than just bytes (16-bit words, floats, strings, 16-bit register pairs) - automatic variable allocations, automatic string variables and string sharing - constant folding in expressions (compile-time evaluation) - automatic type conversions - floating point operations - abstracting away low level aspects such as ZeroPage handling, program startup, explicit memory addresses - 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 - conditional gotos - various code optimizations (code structure, logical and numerical expressions, ...) It is mainly targeted at the Commodore-64 machine at this time. Documentation is online at https://prog8.readthedocs.io/ 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 8 or newer** is required to run the packaged compiler. If you want to build it from source, you'll need a Kotlin 1.3 SDK as well (or for instance, IntelliJ IDEA with the Kotlin plugin). It's handy to have a C-64 emulator or a real C-64 to run the programs on. The compiler assumes the presence of the [Vice emulator](http://vice-emu.sourceforge.net/) Example code ------------ When this code is compiled:: %import c64lib %import c64utils %import c64flt ~ main { sub start() { ; set text color and activate lowercase charset c64.COLOR = 13 c64.VMCSB |= 2 ; use optimized routine to write text c64scr.print("Hello!\n") ; use iteration to write text str question = "How are you?\n" for ubyte char in question c64.CHROUT(char) ; use indexed loop to write characters str bye = "Goodbye!\n" for ubyte c in 0 to len(bye) c64.CHROUT(bye[c]) float clock_seconds = ((mkword(c64.TIME_LO, c64.TIME_MID) as float) + (c64.TIME_HI as float)*65536.0) / 60 float hours = floor(clock_seconds / 3600) clock_seconds -= hours*3600 float minutes = floor(clock_seconds / 60) clock_seconds = floor(clock_seconds - minutes * 60.0) c64scr.print("system time in ti$ is ") c64flt.print_f(hours) c64.CHROUT(':') c64flt.print_f(minutes) c64.CHROUT(':') c64flt.print_f(clock_seconds) c64.CHROUT('\n') } } you get a program that outputs this when loaded on a C-64: ![c64 screen](docs/source/_static/hello_screen.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)