Logitech TrackMan Marble FX

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Logitech TrackMan Marble FX

Post by Archie » 03 Feb 2019 19:40

Ball size: 21/16" (52.5mm)
Interface: PS/2+RS-232
M/N: T-CJ12
P/N: 804251-0000
PnP ID: LGI8049
Year: 1997

Marble FX is often considered to be one of the best Logitech trackballs. Very unusual design looks a bit funny, but convenience of use is tremendous: it's very convenient for long work. Ball and buttons arrangement is quite ergonomic. Additional case opening, opposite to the main operating surface, allows to actually hold the ball between fingers and thumb, when extra precision is needed. Interesting thing is, all the buttons have different direction of travel: left button is pressed downwards, right button at angle, and 3rd. and 4th. pressed sideways. It sounds inconsistent, but in practical use is incredibly convenient.


Ball size 52.5mm, weight 93.2g. Switches - Matsushita AHM19001. Controller with Microchip Technology logo marked 331029-3011 9901SAN.

Ball is supported by 3 grey ceramic 1.73mm bearings. Movement is very easy and smooth. Proprietary Marble technology is used, so red ball have traditional black speckles.

Device is dual-system: native connector is PS/2, but serial is also supported by proprietary MiniDIN-6 to DB-9 adapter. If plugged into serial port, it reports "LGI8049" to Plug-and-Play's Device ID query. For serial connection, all 6 wires are used:


As basic PS/2 operation doesn't support anything above 3 buttons, this device requires switching the port to the extended mode. This means, it's impossible to use red button when Marble FX is connected to modern computer via common cheap PS/2 to USB converter. It seems Logitech was ready to release USB version of this trackball: MouseWare drivers include support for "Logitech USB Turbo TrackMan Marble FX" with VID_046D&PID_C403, but I've never seen it anywhere.

Logitech product sheet:
https://trackballs.eu/media/Logitech/Ma ... rbleFX.pdf

According to iF Design 1998 award page, this trackball was designed by Design Partners company.


Design is patented by USD410638:
https://trackballs.eu/media/Logitech/Ma ... 410638.pdf

Principle of operation covered by patent US5288993:

Further information about Marble technology:

Unfortunately, this device was produced for limited time only. It was included in the lisl of products affected by Gart vs. Logitech patent discussion. Court has ruled out this issue in favor of Logitech in 2001, but T-CJ12 was discontinued at that time.

United States Court of Appeals for the Federal Circuit:

Samuel Gart's patent US4862165:

Teardown gallery on Imgur.com:

Converting to USB interface with 4th. button support: