void display_putchar(char c) {
    if (c == '\n') {
        cursor_x = 0;
        cursor_y += 8;
        if (cursor_y >= 64) display_scroll();
        display_refresh();
        return;
    } else if (c == '\r') {
        cursor_x = 0;
        display_refresh();
        return;
    }

    if (c < 32 || c > 127) return;

    for (uint8_t row = 0; row < 8; row++) {
        uint8_t line = font8x8_basic[c - 32][row];
        for (uint8_t col = 0; col < 8; col += 2) {
            uint8_t px1 = (line & (1 << (7 - col))) ? 0xF : 0x0;
            uint8_t px2 = (line & (1 << (6 - col))) ? 0xF : 0x0;
            uint8_t packed = (px1 << 4) | px2;
            uint16_t offset = ((cursor_y + row) * SCREEN_WIDTH + cursor_x + col) / 2;
            if (offset < FRAMEBUFFER_SIZE) framebuffer[offset] = packed;
        }
    }

    cursor_x += 8;
    if (cursor_x >= 132) {
        cursor_x = 0;
        cursor_y += 8;
        if (cursor_y >= 64) {
            cursor_y = 0; // Wrap around
        }
    }
    display_refresh();
}