I looked some pages with Mist specs, and found only very little info about SD card usage on Mist:
" SD cards
Standard form factor classic SD cards (<= 2GB) as well as SDHC cards (> 2GB) are supported. The use of a 1GB card of a well-known brand is recommended.
The card has to be FAT formatted. If in doubt use a windows PC or even better a device like a digital camera to format the card. "
Now, as there is no floppy attachable, it works with floppy images, similar as HxC, I guess. Therefore is need for FAT formatted card (actually very shallow info - how many partitions supported, etc ... ?).
But what if we want to use SD card as hard disk ? How Mist knows that it should be threaten as hard disk, with all low level access via DMA/ACSI port commands and not as FAT partition with floppy image files ? What is size limit ? Does it use basic ACSI commands, so limit is 1GB, or use ICD commands, when can go over 1GB ?
Is there maybe some "pre-master boot sector", what describes type of data on SD card ?
Does someone wrote hard disk image file directly to start of SD card, and it worked on Mist ?
Or there is some menu where can set it ?
English language is like bad boss on workplace: it expecting from you to strictly follow all, numerous rules, but self bending rules as much likes