SatanDisk project for ATARI ST

Why the name?

• the project name is derived from the name of cards (storage media) which the interface uses (SD cards  = Secure Digital -> SatanDisk)

• the interface also works with MMC cards as they are almost compatible with SD cards in the SPI mode

• it has nothing to do with satanism or occultism ;-)

• was made up by gwEm

Why SatanDisk?

• MMC and SD cards are cheap and noise-less.

• MMC and SD cards with the interface can be powered from the original ATARI ST power-supply (IDE drives need more power so they mostly need another PSU). NOTE

• Because most people would use IDE Devil with a CF-to-IDE adaptor anyway. This way they will save money because they wouldn't need to buy that adaptor.

• Because IDE Devil needs a lot of fixing before it can be used by most users - I figured out that the IDE part of the IDE Devil should be extensively tested and fixed, because some IDE drives act bit different than the others and so they don't work with IDE Devil (for now). The MMC and SD cards are pretty well compatible in SPI mode so there is no need for extensive debuging.

Specifications:

• connects to ACSI port of Atari ST

• up to 4 GB size of MMC/SD card (this is the limit of MMC/SD card AFAIK)

• HDDRIVER compatible

• cheap - price of parts is approx. 15 Euro (+ approx. 12 Euro for the MMC card)

• open-source - free schematics, firmware, sources, so anyone can build it on his own

• uses custom ACSI-to-MCU bridge based on the XILINX XC9536XL to achieve data transfer reliability

• dimensions of PCB: 60 x 42 mm on double-sided PCB

• tested (and works) with STFM (TOS 1.02), STE (TOS 2.06), Mega ST1 (TOS 1.02), Mega STE (TOS 2.05)

• tested with 2 different MMC cards and 2 different SD cards and it works fine

Known bugs (will be fixed in the next FW):

• cold boot issue - when SatanDisk is turned on and the ST is turned on, the ST won't boot from SatanDisk. After one reset of ST the it will boot from SatanDisk without problems

• cards with size >1GB show wrong size in HDDRIVER and therefore they can't be accessed completely (this is caused by larger sector size in cards >1 GB - normal cards have sector of 512 Bytes, but 2GB cards have 1kB sectors and 4GB cards have 2kB sectors)

Please note that even if SatanDisk was tested with 2 different  SD cards and 2 different  MMC cards, I can't guarantee that it will work with all kinds of MMC and SD cards - I just don't have enough time, money and nerves to buy and test all kinds of cards. As it is with attaching a normal HDD to ATARI - it would be good (for you) if you could test the card with SatanDisk to see if it works before you buy it.