[Pcsclite-muscle] SCR333v1 - STCII DFU Adapter - firmware update

Frederic Dumas f.dumas at ellis.siteparc.fr
Fri Dec 30 05:35:03 PST 2022

Hello everyone on the mailing list,

Ludovic invited me to ask my question to the members of this list. It is about the SCR333 card reader, from SCM Microsystems (the company has now become Identiv by merger-acquisition). This hardware, although perfectly compatible with the current standards, is considered "obsolete" by its manufacturer, who therefore no longer offers support for it.

One of these card readers [1], and a few months later a second, advertised themselves as "STCII DFU Adapter" on the USB bus, and became inaccessible through CCID. The matter is identified in the manufacturer's documentation [2]; it would be enough to reflash the reader with the original firmware to fix it.

On its website, the manufacturer no longer provides the firmware. Its online technical support is also unable to find a copy of this firmware.

Does any of you on the list have the SCM's firmware for the SCR333 card reader in your archives?

The Common Access Card web page [3], maintained by a retired US military man, offers firmware for the SCR331 model and another for the SCR3310 model, available for download. Thanks to a nice guy at Cardlogix for redirecting me to this resource.

Do either of these two readers share the same PCB with the SCR333 (i.e. the same firmware)?

More out of curiosity, but also a bit for practical purposes, does anyone also know what the trigger might be that causes the firmware to "corrupt"? Could an electrostatic shock have altered the flash memory of the STC microcontroller? Or would the old firmware versions be sensitive to a magic word that they see passing over the USB bus? Without understanding the cause, I could only observe that "suddenly" one or the other drive was no longer seen as a CCID device.

Thanks in advance for any advice!


[1] SCR333 V1 ; the PCB reads: rev 1.1 12 DEC 2002
[2] Smartcard Reader - Installation & Troubleshooting Manual - Version 1.0 - November 17, 2008, p.17
[3] https://militarycac.org/cacdrivers.htm

Frédéric Dumas
f.dumas at ellis.siteparc.fr

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