Marconi RB2 Trackerball

The Acorn Domesday branded RB2



The Marconi RB2 trackerball (or Marcus trackerball as it was later known) was available as a standalone device for both the BBC Micro Model B and the BBC Master.  The following PDF is the user manual for the BBC Micro Model B version and includes the technical details of the quadrature output and pin-out of the user-port connector:

Marconi RB2 User Guide - BBC Model B (PDF file 500KBytes)


When used with the AIV system the trackerball software is built into the Acorn VFS ROM, however Marconi released both a ROM and a floppy disc to support the device when used standalone (the software mentioned in the user guide is provided on the floppy disc).  Both the ROM and the floppy disc (BeebEM compatible SSD file) are available below:

Marconi RB2 ROM

Marconi TBALL floppy

The following picture shows the RB2 branded as the 'Marcus' trackball. These versions have essentially the same mechanics as the Acorn variant, however the circuitry is typically for PS/2 mouse interfaces:

The Marcus RB2 Trackerball

The following PNG is an enhanced 600dpi version of the Acorn Tracker Ball logo sticker found on the original Acorn branded RB2 trackballs:

Scan of the Acorn RB2 sticker

The following file contains an Adobe Illustrator version of the sticker along with a 2400 dpi PNG file. These files are to scale and are suitable for printing:

Acorn RB2 Sticker vector


The following image shows the solder-side of the single-sided PCB using the the RB2:

Marconi RB2 PCB