Virtually all computers in room 255 have a local copy of Mathematica installed. To use it, the computer has to be all the time connected over the network to one of UD mainframes which is Mathematica's licence server. Each time somebody uses such a copy of Mathematica, this counts against the total number of licences that UD has. The licence server works transparently except when it fails or when the number of users exceed the limit (currently 21). Save your work frequently since small network stoppages will crash Mathematica.

To start Mathematica on one of Windows PCs, just go to `Start
Programs Mathematica`. To print,
go to `File Print` and a typical MS Windows
printing window will appear. Since at this moment all users access
PCs in SHL 255 as ``guest", create your own subdirectory to save
your work.
To start Mathematica
on a Linux computer open an X-window and type `mathematica &`.
When you print, the print window is similar as on composers.
It is sufficient to have in ``Print to" line the command `lpr`
to print on one of the printers in SHL 255.