IIgs with unknown ADB device...?

[labelas@hotmail.com (Labelas Enoreth)]

Today I came across a IIgs which has this unusual item plugged into it's
ADB port between the keyboard and the computer. It appears to be a
'dongle' of some kind, like what I've seen for some of the more expensive
software.
It basically looks like a short (1") adb cable that plugs into the back of
the computer, ending in a small rectangular box that has a second ADB port
on it to chain through, presumably. I took it apart out of idle curiousity
and there isn't much to it...the board itself has �MSSI ADB REV H...
There appears to be an oscillator(12mhz?), two...uhm, resistors I think,
and a large square chip which has on it:
<large 5 or S>MSSI20V8
22368069331KA
ADB REV P1
�INTEL80�SIG87

and a smaller chip with a logo like two waves and
33AE
93C46
MB

anyway, has anyone ever heard of a dongle for the IIgs, or is this
something else, which adds another functionality, perhaps to the keyboard
or something?
Any help would be appreciated.