void test_read(void)
{
    char cbuf[255];
    char d_buf[512];
    int i;
    int line = 0;
    int pos = 0;
    int lines_per_screen = 20;
    int addr;

    addr = 0x0;

    ata_read_sectors(addr, 1, &d_buf);
    while(1)
    {
        for(i = 0; i < lines_per_screen; i++){
            snprintf(cbuf, sizeof(cbuf), "%03x: %02x%02x%02x%02x %02x%02x%02x%02x %c%c%c%c%c%c%c%c", pos,
                d_buf[pos+0], d_buf[pos+1], d_buf[pos+2], d_buf[pos+3], d_buf[pos+4], d_buf[pos+5], d_buf[pos+6],
                d_buf[pos+7], printc(d_buf[pos+0]), printc(d_buf[pos+1]), printc(d_buf[pos+2]),
                printc(d_buf[pos+3]), printc(d_buf[pos+4]), printc(d_buf[pos+5]), printc(d_buf[pos+6]),
                printc(d_buf[pos+7]));
            lcd_puts(0,line++, cbuf);
            lcd_update();
            pos += 8;
        }

        line = 0;
        if(wait_for_button() == 8)
        {
            pos -= 16;
            if(pos<0)
                pos = 0;
        }
    }
}