mirror of
https://github.com/irmen/prog8.git
synced 2024-11-19 11:32:17 +00:00
115 lines
4.2 KiB
Markdown
115 lines
4.2 KiB
Markdown
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:
|
|
|
|
|
|
|
|
|
|
One of the included examples (wizzine.p8) animates a bunch of sprite balloons and looks like this:
|
|
|
|
|
|
|
|
Another example (cube3d-sprites.p8) draws the vertices of a rotating 3d cube:
|
|
|
|
|
|
|
|
If you want to play a video game, a fully working Tetris clone is included in the examples:
|
|
|
|
|