What are the requirements for the SD card?

Is there a minimum size? Speed?
I have a few old cards I’d like to use as spares for the printer, but it won’t recognize them.

Format FAT32. No minimum that I'm aware of. Larger than 4GB will not update firmware, but can be used for printing.

I have some smaller cards, 1GB and 512MB, that it won't read.  Any idea why?  

same problem for me

SD card 1Gb FAT 32 format, doesn't work

Format FAT32. No minimum that I'm aware of. Larger than 4GB will not update firmware, but can be used for printing.

I successfully updated fw with 32GB FlashAir III (printers hw01 and hw04)

I successfully updated fw with 32GB FlashAir III (printers hw01 and hw04)

Good to know.. I have not tried any larger cards for FW yet..

I upgrade the firmware without worries with 16GB FlashAir lll

[Added more functional/nonfunctional cards]

I've got a bunch of cards that don't work:

PNY 128M (yes, MB) card, doesn't work

SanDisk 8BG SDHC Class-4 card - doesn't work

Crucial 1GB

Lexar 128MB (yes, Megabyte)

Kingston 16GB SDHC Class 4

SanDisk 512MB MicroSD in adapter

Yes, I've formatted with FAT32, full or short, makes no difference.

 

I've also got three cards that work:

Factory original Zortrax card

1GB Kingston SD Card (NOTE!  Formatted for FAT, not FAT32!)

Kingston Micro SDHC 8G card in adapter

All use the SD card slot on my Dell XPS8500

This makes no sense at all, there's something screwy about the "any size as long as it's FAT32" spec.

M200 is running FW 1.0.0