The computer system is one of the hardest things for new students to get used to, but do so they must, as the much of their work will be computer-based.
Starlink
The Observatory hosts one of the nodes of the Starlink computer network, which is run by PPARC and which links the principal astronomical institutes in the UK. Much of the computer hardware in the Observatory belongs to Starlink, some to the ATC, and an increasing amount to the IfA but it is all available for use by students. The basis of the Starlink node is a cluster of PCs running LINUX and DEC/Compaq/HP/Whoever-owns-them-this-week Alphas. All the machines have Unix based operating systems, although there are some differences between the Alpha and Linux command languages, such as the compiling commands.
In addition to providing hardware, Starlink also supplies and supports software, such as subroutine libraries, graphics and data reduction packages.
A Starlink Local Users Group (SLUG) meets every six months. This is a formal forum for the discussion of problems relating to the use of the Edinburgh Starlink node and its future development, in the presence of a representative from Starlink. On the same day as the SLUG there is a meeting of the Local Management Committee (LMC), which discusses points raised by users at the SLUG and draws up a formal ``wish list'' of desired hardware. Your student representatives on this committee are currently Michael Davidson and Ben Panter.
User-names and accounts on the computer are obtainable from the system manager of the Starlink node, John Barrow, after his introductory talk which he will deliver shortly after you arrive.
Default Setup
There has recently been a complete overhaul to the default setups given to new users. They should now work and look similar on both Linux and Alpha machines. Some things you might like to do when you first get here to get yourself accustomed to the computers is to change things such as your colour scheme. See Unix User Note 9.2 (intra.roe.ac.uk/atc/computing/docs/uun/uun009.html).
Disk space
All users are given a certain amount of file-space on a common user disk and they cannot exceed this quota. In addition, there are ``Scratch Disks'', which are designed for temporary storage of data under reduction. See John Barrow or Horst Meyerdierks if you need some ``Scratch'' space, or desperately need your home space increasing.
Exabytes, DATs and Magnetic tapes
The computer system crashes from time to time, which can result in the loss of files. So, to prevent the loss of valuable information, it is highly advisable to make regular ``back-ups'' - i.e. to copy files onto Exabyte - high-quality 8mm video cartridges - DAT or magnetic tape. Exabytes and DATs hold an immense amount of information, the biggest ones can hold up to 4GB. They are available on request from Liz Gibson or from the stationary cupboard. Far cheaper are CD-R disks, which can be written from most of the newer LINUX boxes in the department.
The System Manager makes routine backups of the user disks, but not the ``Scratch'' disks, so it is important to remember to back-up your scratch space regularly, say once a month. It is also a good idea to cycle your back-up tapes and not put your trust in just one, as they can be quite unstable. Sometimes they can lose your data completely or become readable only by the machine that wrote them. In general DATs are faster and cheaper and Exabytes are more stable.
The Starlink network enables the sending of electronic mail (email) messages between users on the same node, at different nodes and, through its connections to other international computer networks, to research institutions throughout the world. Email is a very convenient means of communication, both within the Observatory and to colleagues elsewhere. To access your email account, type ``pine''. Your address at the observatory will be login@roe.ac.uk
Postgraduate Laptops
There are currently several Toshiba Satellite Laptops available for postgraduate use. These are equipped with dual boot Linux/Windows operating systems and can be connected to the local ROE ethernet. To arrange to use one of the laptops, contact your student representative (Emma Taylor 2003-2004).
Computer Training
The Institute organises introductory Unix courses for all new research students. In addition the Site Manager, John Barrow will give a short talk on Starlink and the Observatory's computing facilities within the first few weeks of the October term. The Library has some books on how to program in FORTRAN, C and IDL which are the most common languages used. Often the most efficient way of solving computing difficulties is to ask for help from other students. For hardware problems it is best to consult Horst Meyerdierks or John Barrow. The University also runs good programming courses for beginners - these are available through the Transferable Skills program (see later).
Computing Webpages
A large amount of information on all aspects of computing provision at ROE is available on the Web - see http://intra.roe.ac.uk/atc/computing/ and links therefrom. Particularly useful are the online User Notes, to be found by following the Documents link.