📜Legacy Device & Historical Reference

15.1 Corporate History & Patents

Company Timeline

• 1996: Co-founded CNS Co., Ltd.

• 2011: Spun off as CNS Korea.

• 2013: Established IODD Co., Ltd.

Intellectual Property

• Patent (2nd Password): "Device password setting for preventing duplication of encrypted devices." (Patent-2022-0021783). Supports 4-38 digit passwords.

• Patent (Virtual ODD): "Memory device recognizable as an optical disk drive and its driving method." (No. 0993935). Valid until September 9, 2028.

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15.2 📜 Legacy Device Details (2531 / 2541 / MINI)

The legacy models use different physical controls and firmware structures compared to the modern ST/MINI PRO series.

Hardware Characteristics

• Modern Series (ST300/400, MINI PRO): Feature a color LCD (128x160 dots) and support Multi-LUN (Mount up to 3 VHDs, 1 ODD, and 1 Physical HDD simultaneously for a total of 5 devices).

• Legacy Series (2531, 2541, MINI Legacy): Support up to 4 Virtual Drives, 1 ODD, and 1 Physical HDD simultaneously.

• IODD 2531: Uses a 3-way Jog Dial (Up/Down/Click) and a side back button. Supports 2.5-inch SATA HDDs up to 9.5mm. It shares the same architecture as the ZM-VE300. Material: Aluminum and PC (Plastic).

  • Tip: If installing a thinner 7mm drive in a 2531, a spacer is required for a secure fit.

• IODD 2541: Uses 12 Touch Keys. Based on the ZM-VE400 architecture but with improved hardware.

• IODD MINI (Legacy): Uses 12 Tactile buttons and a Micro-B USB 3.0 connector. Uses M.2 SATA 2242 (42mm) SSDs.

• Tip: For older 2541 units with touch sensitivity issues, placing a thin sheet of plastic or paper between the HDD and the front body (not the cover) can improve responsiveness.

Additional Modern Features (ST/MINI PRO)

• Bitmap File Viewer (Experimental): Supports viewing small bitmap images (under 128x160 resolution, 1/16/24-bit color depth).

• Text Viewer: Supports reading .txt files in UTF-16 (UCS-2) and ASCII formats.

• Standalone Mode: Allows users to configure settings or browse files using a USB power bank without connecting to a PC (Hold key [5] or [M] during connection).

• Admin/User Login: When encryption is active, the first digit of the password entry identifies the user: 0 for Administrator, 1 through 4 for standard users. (e.g., if the admin password is 1234, enter 01234).

Legacy-Specific Features (2531 / 2541)

• Force USB 3.0: A menu option to force the device to maintain a USB 3.0 connection even in harsh conditions where it might otherwise downshift to USB 2.0.

• Instant Save: Quickly saves the current configuration and loading state.

• Fixed/Removable filenames: Use .VHD for fixed disks and .RMD for removable media (Legacy only).

Emergency Recovery Procedures

Device Type	Procedure	Description
ST / MINI PRO	Force Recovery	Hold [9] + [Enter] for 7 seconds while connecting. Re-flashes current firmware.
2541 / 2531	Tact Switch	Open back cover, hold internal tact switch for 7s while connecting.

Emergency Reset For 2541 (Tact Switch)

If the device fails to initialize or becomes unresponsive during a firmware update, follow this hardware reset procedure (requires opening the device):

1. Open the back cover of the IODD.

2. Locate and press the tact switch (reset button) on the internal PCB.

3. While holding the switch, connect the USB cable to the PC.

4. Continue holding the switch for about 7 seconds.

5. Release the switch and wait for approximately 1 minute for the system to recover.

Specific Hotkeys (Legacy)

Device	Action	Hotkey
2531	Rescan Files	Long press Jog Up (3s)
2531	Power Down	Long press Jog Down (3s)
2531	Enter Menu	Long press Jog Center (3s)
2531	Detach All	Long press Back/Up (3s)
2541	Select File	[5] or [6] ([6] maintains loading state on newer firmware)
2541	Power Down	Long press [1] (3s)
2541	Reboot	Long press [3] (3s)
2541	Rescan Files	Long press [4] (3s)
2541	Detach All	Long press [7] (3s)
2541	Disable WP	Long press [0] (3s) - Reboot and temporarily disable Write-Protection

• Tip (2531): On firmware 1558 or higher, the loading state is saved automatically. For older versions, use the Power Down hotkey to save the state manually.

• Tip (2541): Button [6] for maintaining loading state requires firmware 6(7)9-05 or higher.

Startup Keys (2531 Only)

During startup (when connecting the USB cable), holding the following keys will force a specific mode:

Key	Resulting Mode
Jog Up	Start in CD-MODE
Jog Down	Start in HDD-MODE
Jog Center	Start in DUAL-MODE (Resets loading state)
Back Button	Start in Write-Protected mode

Firmware & Partition Limits (Legacy)

• NTFS vs FAT: Separate firmware versions exist (ending in N or F) depending on the first partition's file system.

• 6x vs 7x Versions (2541): 7x versions include enhanced security against brute-force password attacks. Note: Data must be backed up when switching between 6x and 7x.

• 2TB Limit: When using virtual drive functions (ISO/VHD), a maximum 2TB partition size is supported on 2531/2541/MINI models.

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Advanced VHD Naming Conventions (IODD 2531 / 2541 Only)

Model Limitation: The following tips for controlling modes via filenames (&D, &DW) apply only to IODD 2531 and 2541 models. These features are not supported on newer models like ST400, LK100, or MINI PRO.

For legacy models (2531/2541) and specific automated workflows, the filename of a VHD can control the IODD's behavior upon mounting:

• Standard Mounting: filename.VHD or filename.VMDK (Mounts as a fixed disk). iODD supports fixed-size VMDK files (can be created by renaming a VHD to VMDK).

• Removable Mounting: filename.RMD (Mounts as removable media/flash drive).

• Dual Mode (Write-Protected): Append &D to the filename (e.g., Win2Go&D.VHD). Mounts in Dual Mode with the physical HDD write-protected.

• Dual Mode (Write-Enabled): Append &DW to the filename (e.g., Win2Go&DW.VHD). Mounts in Dual Mode with the physical HDD write-enabled.

Virtual FDD Support

IODD supports uncompressed floppy disk images in IMA, IMG, BIF, or VFD formats. If using .IMG, .BIF, or .VFD, rename the extension to .IMA for best compatibility.