Each neutron scattering instrument at ISIS has a VAX computer (sometimes known as a FEM - Front End Mini) which controls the data acquisition. These computers, together with other VAX computers at ISIS, are closely linked together in a network known as a cluster which gives them immediate access to files stored on each other’s disks. Most of the computers in the cluster run an operating system called VMS. Information on how to use this operating system may be found elsewhere. However, command names are mostly easy to guess, and also there is a good help system which is invoked by typing HELP. At the present point in time some of the newest computers in the ISIS cluster are Alpha computers. These are very fast, but software compiled to run on the older VAX computers will not run on them. The ATLAS data analysis suite has been adapted so that it can run satisfactorily on either type of computer. However, users may not find that this is the case with all software.

Users of ISIS are encouraged to obtain their own usernames on this computer system. This may be easily done by just completing an application form which may be obtained from the computer support office (room 1-37 in building R3). The convention for naming these usernames is to take the initials of the user’s name and to add a two digit number. For example the username for Dr. A. N. User would be ANU01 (or ANU02 if the username ANU01 already exists).

In order to log on to a simple terminal, the user presses the <BREAK> key until a prompt like Local> is obtained. This indicates that a connection has been made to a terminal server. In order to connect through this server to the LAD instrument computer you should type C LAD . Other computers in the cluster to which users may also connect include ISISE, ISVS1 and HORUS. The LAD instrument computer is not as powerful as these computers and hence users should not log on to the LAD computer once their experiment has been completed.

In order to use the ATLAS data analysis suite the user should first edit a file LOGIN.COM (which must be in the top level directory [ANU01] ) to contain the following line:

$ @LAD$DISK:[LADMGR]USER_LOGIN

The file LOGIN.COM runs every time the user ANU01 logs on.

Last Updated 09 Nov 1998