Rookie Drive NX
This page was last modified 15:57, 14 July 2021 by Sdsnatcher73. Based on work by Mars2000you and Pac.




The Rookie Drive NX interface developed by user Xavirompe is the first complete USB storage device for the MSX standard.

This interface lets us to connect floppy disk drives, pendrives and hard disks. It is based on the file manage and control chip CH376S which supports FAT12, FAT16 and FAT32 file systems.

It includes

  • a 192kB ROM that contains several drivers (see Specifications), a bootloader and a recovery utility
  • a flash memory which allows driver and/or Disk ROM updating
  • a switch for ROM disabling (replaced by a jumper inside the cartridge on versions released since 2021)

Official price: between 55€ and 65€ according the destination)


When starting, the Rookie Drive firmware will try to detect

  • the presence of USB disk drive with UFI protocol (if so, the system will load the floppy disk driver)
  • the connection of a storage device to the USB port of the Rookie Drive (if so, the system will automatically switch to disk image mode)

If these detections are both negative, the firmware will start a code that will detect the type of MSX:

  • when a MSX1 computer is used, the 720kB disk emulation will be launched
  • when a MSX2 or higher computer is used, the Nextor driver will be launched if you have at least 128kB RAM.

At boot time, you can “force”

  • the loading of 720kB disk emulation by pressing the “D” key ("7" key in firmware versions released before 13 September 2017)
  • the loading of Nextor driver by pressing the “N” key
  • the loading of USB FDD mode by pressing the "F" key
  • boot mode 1 for disk image mode by pressing the TAB key (useful as an alternative to device unplugging when you have configured boot mode 3 or 4 if you don't want the corresponding file to be mounted at boot time)

More options are available at boot time. Press the "H" key when booting to access the Rookie Drive Boot HELP menu.

See also RookieDrive BASIC



Rookie Drive NX PCB 1.3
Rookie Drive NX PCB 1.2
Rookie Drive NX PCB 1.1
Rookie Drive NX 1.2.1
Rookie Drive NX 1.1 biue
Rookie Drive NX 1.1 red
Rookie Drive NX switch
Rookie Drive NX connectors


Note: When an USB device is connected, the Recovery menu will display the name of your USB device on the second line.

Rookie Drive Boot HELP menu - page 1
Rookie Drive Boot HELP menu - page 2
Rookie Drive Recovery menu


Rookie Drive NX is released with Nextor built-in and contains 2 or 3 different drivers in the same ROM:

  • Rookie Drive 720
    • Floppy disk emulation based on MSX-DOS 1
    • USB support for formatted devices in FAT12, FAT16 and FAT32.
    • 720kB disk images.
    • CALL instructions to handle disk images - see RookieDrive BASIC
    • It works on MSX1 computers and higher.
  • Rookie Drive NX
    • Mass storage device with Nextor operating system (needs minimum 128kB, usually for MSX2 computers).
    • Disk ROM of 320kB (“reflasheable”) to boot the operating system.
    • USB port for storage devices (pendrive or hard disk) formatted in FAT12 or FAT16.
  • Rookie Drive FDD BIOS (added by Konamiman since version of the firmware released on 8 January 2019)
    • USB floppy disk controller compatible with UFI protocol (2DD & 2HD floppy disk drives support)
    • USB floppy disk controller - disk image mode (since 01/07/2021)
    • CALL FORMAT is modified and new CALL instructions are available - see RookieDrive BASIC