Recommended flash storage memory formatting

4 Feb 2021

We recommend using pseudo-SLC (Single Layer Chip) instead of MLC (Multi-Layer Chip) MicroSD cards. MLC may be lower cost and slightly faster performance, but pseudo-SLC is far more stable and provides a much longer life expectancy.

Original article from 25 Feb 2008:

Warning: The following information can affect data (files and folders) contained on a storage memory device used with the Field PC (such as the internal flash memory; an inserted PCMCIA, CF, or SD card; or an attached USB memory device). Back up all data and installed software on the storage memory device to a desktop PC before following any instruction provided below.

Memory Formats

"FAT16" or "FAT" (not "FAT32") is currently the most recognized and recommended memory format for use in the Microsoft Windows Mobile, Windows CE, and DOS operating systems used on the Juniper Systems ultra-rugged Field PC products.

"FAT32", "NTFS", and other memory formats may also be recognized by and used in these operating systems on the Field PC, but may not be fully compatible with older Field PC models, and may not be used to load system files (operating system or firmware files, often with CAB or BIN file extensions).

If a storage memory device is not recognized by a Field PC, or cannot be used to load a system file, then the device may need to be re-formatted to "FAT16" or "FAT" format.

Formatting Storage Memory

A third party software application can be used to format the storage memory device while in or attached to the Field PC. One such application is

CNetX Flash Format as described on our "Flash Memory Maintenance" FAQ web page.

If you are using an Allegro CE Field PC with the Microsoft Windows CE .NET 4.1 operating system, the Storage Manager control panel applet can be used to format storage memory.

If you are using a Field PC model with a native DOS operating system, you can use the DOS "format" command to format a storage memory device.

The "Format..." utility built-in to desktop versions of the Microsoft Windows operating system can be used to format mobile storage memory devices ("FAT" is "FAT16" in this utility), but may not provide the correct formatting for some Field PC models (PCMCIA-ATA). See below for more information.

Storage Memory Card Not Recognized in DOS

The DOS operating system on older model Field PCs does not recognize storage memory cards larger than 2GBs. Also, some smaller storage memory cards may not be the correct format ("ATA") to be recognized by the DOS operating system even if formatted correctly (to "FAT" or "FAT16").

A utility program called ATAINIT.EXE (from System Soft) was included in the "C:\UTIL" folder on all Allegro CE/DOS Field PC and Allegro DOS Field PC model units shipped after January 1, 2002. This program scans the storage memory card to find the correct physical parameters to use to be recognized in DOS (such as number of sectors, cylinders, etc.), and then prepares the card for use.

Follow these steps for formatting a PCMCIA or similar card for use in DOS on an older Allegro Field PC:

  1. Boot the Allegro to the DOS operating system prompt. If you are in Windows on the Allegro, tap on the Start Menu, Programs, and then Boot to DOS. Select Yes to continue with saving the system.
  2. At the DOS prompt on the Allegro, type "ATAINIT D:" or the drive letter corresponding with the card, and press Enter to run the program.
  3. A display will appear showing information for the storage card. To see all the information, you can press the Yellow key and Up arrow on the keyboard to pan the display to view text that has already scrolled past. Press Enter to accept the values and continue.
  4. When the system asks, "Do you wish a compact format?" press "N" for no. ATAINIT will then re-initialize the card for formatting.
  5. A message will display stating, "Partition table successfully written. BPB Boot sector successfully wiped. Proceed with a DOS `Format /U` command." The card is now accessible in DOS, though it is recommended to completely format the card before using. Continue below to completely format the card.
  6. At the DOS prompt, type "A:" and press Enter to change to drive A. This will help ensure that the Allegro`s internal storage "C_Drive" will not accidentally be formatted. To format the inserted storage card, type "FORMAT D:" or the drive letter corresponding with the inserted card, and then press Enter. Press "Y" for Yes when asked to proceed with the format.