Commodore 64 Rust Libraries

Various C64 Rust utilities that I coded while learning Rust.

REU library

Basic REU wrapper

Some obvious REU operations wrapped into Rust functions:

let reu = ram_expansion_unit::reu();
reu.set_range(1024, 0x050000, 1000);  // prepare REU working range
reu.pull(); // get data from REU into RAM
reu.push(); // put data from RAM to REU
reu.swap(); // swap RAM and REU
reu.fill(1024, 1000, 32); // clear screen using REU DMA
reu.fill_reu(0x030000, 10000, 0); // fill some REU address with 0s

REU allocator

A simple memory allocator returning 24-bit pointer that knows its block size, for cleaner syntax. Allocated chunks get properly dropped. Minimum allocation size = 256 bytes.

let reu = ram_expansion_unit::reu();
reu.init_allocator();  // prepare BAM in REU
let screen_memory = reu.alloc(1000);  // alloc 1000 bytes somewhere in REU
screen_memory.push(1024);  // push RAM starting at 1024 into REU chunk
...
screen_memory.pull(1024);  // restore REU chunk into RAM starting at 1024
// screen_memory will be deallocated properly

Array stored in REU

u32 indexable array that is kept in REU, with all Rust goodies. The size of the array is limited only by REU size.

#[derive(Clone)]
struct GameUnit {
    number: u8,
    speed: u8,
    health: u8,
    x: u16,
    y: u16,
}

pub fn test_reu_array() {
    // Allocate 100,000 GameUnit elements 10 elements will be cached in RAM
    let mut array = REUArray::<GameUnit>::with_capacity(100_000, 10);

    for i in 0..100 {
        array.push(GameUnit {
            number: i as u8,
            speed: 1,
            health: 2,
            x: 3,
            y: 4,
        });
    }

    array[50].speed = 0xa;
    array[50].health = 0xb;
    array[50].x = 69;
    array[50].y = 11;

    let sixty_nine = array.iter_mut().filter(|unit| unit.x == 69);

    for u in sixty_nine {
        println!("{} Unit at x=69: ({},{})", u.number, u.x, u.y);
    }
}

Ultimate 64 speed registers

Set clock speed of Ultimate 64:

    ultimate_64::get().set_speed(ultimate_64::Timings::MHZ_48.bits());
    ultimate_64::get().set_enable(ultimate_64::Turbo::ENABLE.bits());

A Hires screen library

pub fn test_hires() {
    const HIRES: *const C64HiresScreen = 0x2000 as _;
    const COLORS: *const C64TextScreen = 1024 as _;

    let vic = c64::vic2();

    unsafe {
        vic.border_color.write(COLOR_BLACK);

        (*COLORS).clear(32);

        plotek::show(cia2::VicBankSelect::VIC_0000, ScreenBank::AT_0400);

        (*HIRES).clear(0);

        for i in 0..40 {
            (*HIRES).line((0, 0), (i * 8, 199));
        }
    }

    wait_for_return();

    plotek::hide();
}