Hardware-First
CPU registers, bank boundaries, and processor modes are first-class language concepts. Write code that maps directly to 65816 instructions with full control over the hardware.
Type Safe
Catch bank overflow, mode mismatches, and size errors at compile time. Explicit type conversions and register-aware type checking prevent entire classes of 65816 bugs.
Zero Abstraction Cost
Every high-level construct compiles to efficient assembly matching hand-written code. No runtime overhead, no hidden allocations, no surprises in the generated output.
Write for the hardware
R65 gives you direct access to CPU registers, memory banks, and processor modes — with the safety of a modern type system. No runtime overhead, no hidden abstractions.
Compiles to clean WLA-DX assembly that reads like hand-written code.
#[interrupt(nmi)]
fn vblank_handler() {
dma_transfer(VRAM_BUFFER, 0x0000, 256);
FRAME_COUNTER++;
}
fn update_sprite(id @ A: u8, x @ X: u16) {
let offset = (id as u16) * 4;
OAM_BUFFER[offset] = x as u8;
}