For now are only prototypes. All cards are still possible to mount the connector (IDC to FlexiBridge) or edge connector (standard connector EP without the mediation of the bridge).
The tab holes are in the same spacing which is in the drive 3.5 ".
At the top of the stack are floppy drives.
The next cards, you can add one below the other, combining them with distance spacers.
Housing for the "tower" is not planned.
If all the "floors" will work, then I plan to design one card with all the features of each prototype cards.
At the moment, "tower" has a working interface EXDOS and two floppy drives.