Sysmocom designed and sells a smart card reader with 8 slots for SIM sized
cards (2FF form factor). It is the
sysmoOCTSIM
I received such a reader a few days ago (thanks Harald W.). In my case the reader has a nice aluminium casing to protect the electronic.
I added the reader in my list at: sysmocom_sysmoOCTSIM.
8 slots
The reader has 8 slots. From the CCID USB descriptor:
bMaxSlotIndex: 0x07
The index starts at 0 so a maximum of 7 indicates 8 slots.
And it declares that it can support 8 slots busy at the same time.
bMaxCCIDBusySlots: 8
So it is possible to use the 8 slots at the same time.
This device is the only one to have 8 slots in my list: https://ccid.apdu.fr/select_readers/?bMaxSlotIndex=7
You can also display the reader list sorted by bMaxSlotIndex field to easily see the other readers that have more than 1 slot.
Free Software Firmware
The reader firmware is free software (or open source if you prefer this denomination). The license is GNU GPL 2 or a later version.
The git repository is
https://git.osmocom.org/osmo-ccid-firmware/
The bug tracker is
https://osmocom.org/projects/osmo-ccid-firmware
The only other free software CCID firmware I know of is Tian Tian Xiang Shang used in the GnuK project (An Implementation of USB Cryptographic Token for GnuPG).
CCID driver limitation
My CCID driver does support multi-slots readers since version 0.9.2 released in 2004.
But the driver is limited because it does not support using the slots at the
same time, even if the reader declares it supports it.
pcsc-lite has support for simultaneous multi-slot. But the driver tells pcsc-lite that simultaneous multi-slot is not supported. See this code: https://salsa.debian.org/rousseau/CCID/-/blob/master/src/ifdhandler.c#L490
Of course I tried to modify the code of the CCID driver to tell pcsc-lite that simultaneous multi-slot can be used. But then the driver is confused by mixed USB frames. I then remembered why this support was disabled.
Improvement
Adding support of simultaneous multi-slots is possible. That will require
some work on the CCID driver.
If you want or plan to use such a reader with pcsc-lite on GNU/Linux or another Unix system then contact me so we can discuss what you can do.
Conclusion
I sometimes receive requests about configurations with a lot of smart card readers. Using an 8 slots reader can be part of the solution. This reader requires the use of only one USB port and has its own power supply unit.
The reader firmware is Free Software and I like that. It can only be a good point in the selection of a smart card reader.