Your flash drive has a capacity of more than 4 gigabytes, for this reason it does not have a FAT16 menu, use a small flash drive and then the FAT16 (FAT) option will appear in the formatting menu. My friend, I myself encountered this problem and the only solution was to use an old flash drive with a small capacity.
Hi All,
READ THIS TO THE END AND PAY ATTENTION TO THE WARNINGS GIVEN - YOU WILL BE ERASING DRIVES FROM THE TERMINAL OR COMMAND LINE AND IF YOU DON’T PAY ATTENTION YOU COULD WIPE IMPORTANT INFORMATION BY BEING HASTY. I HAVE TESTED THESE COMMANDS MYSELF AS I WROTE THIS AND KNOW IT WORKS SO TAKE NO RESPONSIBILITY FOR YOUR ERRORS.
Further to my earlier post about how to format a USB flash drive to MBR FAT-16 on MacOS I should have noted that due to the inherent limitations of FAT-16 (which only supports a maximum volume size of 4GB) this will only work for drives with a capacity of 4GB or less.
The command line instructions I gave assumed you would be creating a single volume on an appropriately sized drive - obviously using a 4GB or smaller stick will result in a 4GB or smaller volume. Apologies for not taking into account that the modern USB sticks most people have access to are much bigger than that.
There is, however, a way to use a larger capacity USB drive for this purpose - you just have to specify the desired FAT-16 volume size you want and ignore the rest of the available space.
As per my earlier post - REMOVE ALL EXTERNAL DRIVES CONNECTED TO YOUR COMPUTER TO AVOID ANY CONFUSION. YOU WILL BE ERASING A DRIVE - YOU DO NOT WANT TO DO THIS TO THE WRONG DRIVE
On MacOS the terminal window commands to do this are:
diskutil list external
This will display a list of attached external drives - there should be only one if you followed the advice above
Make a note of /dev/disk# for your USB stick
diskutil partitionDisk /dev/disk# 2 MBR “MS-DOS FAT16” [name] 2048M FREE X 0
Replace the hash (#) in the above command with your device number from earlier and replace [name] with any 8 character or less all caps name eg ARYLIC for example:
diskutil partitionDisk /dev/disk4 2 MBR “MS-DOS FAT16” ARYLIC 2048M FREE X 0
I have tested this on a 16GB USB stick on a computer running the current MacOS and it works as advertised.
For Windows users the situation is the same. You will not even see the FAT-16 formatting option if the drive you are using is bigger than 4GB.
Open a Command Prompt (CMD) window and enter diskpart
You will be asked if you want to allow the diskpart application to run - do so.
When the diskpart app has started in a new window the prompt should change to DISKPART>
Here you will enter list disk
You will be presented with a list of connected disks. Look at the list and determine which one corresponds with your USB drive - in my case the 16GB drive showed up as Disk 2 with a capacity of 14GB
Enter select disk # where the hash (#) is the disk number you want to affect
You will be told that Disk # is now the selected disk
Enter list part to get a list of existing partitions - you will need to delete ALL existing partitions
You do this by selecting the partitions from the highest number downwards and repeatedly deleting the partitions until there are none left. In my case there were two partitions so my sequence was:
list part
select part 2
delete part
list part
select part 1
delete part override
Most often the first partition is a protected system partition and will require the “override” extension to force the command to work. Now if you do a list part there should be no partitions to show - if there are, continue deleting them until all are gone
Now you will create a partition of a size that can be formatted as FAT-16 by entering:
create part primary size=4000
Do a list part to make sure the partition is created and then enter exit to leave the diskpart application.
At this stage you will probably need to pull out the USB stick and reinsert it to get Windows to recognise it and assign a drive letter to it. As the drive is unformatted it will offer to do this for you - turn the offer down by clicking on the “Ignore” button. Open the Windows File Explorer and have a look to see what drive letter has been allocated to your drive.
Go back to the command prompt window and enter
format %: /FS:FAT/Q
substituting your drive letter for the percent sign (%) - in my case this was D so the command became
format D: /FS:FAT/Q
And now you have a valid FAT-16 volume on a drive bigger than 4GB. Again I just tested this using the same 16GB USB stick on a Windows 10 machine and it works as it should.
2 Likes
hi, I put a pen drive formatted fat16, but the upgrade don’t start
Hello, if the firmware version is lower than the previously installed one, then this may happen. You also need to use a flash drive of 4 gigabytes or less.