Off-Line Internet
from CD-ROM or Harddisk

A Timesaver Proposal to CytometryNet Sites

G.Valet


  • Internet Operation
  • CytoRelay
  • 1. Off-Line Internet Concept

    - Internet browsers permit the off-line addressing of HTML files on hard disks (1) or CD-ROMS (2). This feature can be used to set-up all HTML files of a server node in such a way that they can be viewed without modification on the server node itself as well as off/on-line from CD-ROMs or computer harddisks.

    - The FTP download of HTML, image and audio/visual files onto computer harddisks is of particular interest because it can be automated. Inspection of the downloaded information occurs at computer speed i.e. it is not hampered by slow network reaction times.

    - The file set up on the Internet server node is such that all calling commands (href=, src= ) in HTML files do not contain upstream directory trees because this information is automatically appended at the on-line site or by the file call command (file:///) in the off/on-line situation on harddisk or CD-ROM.

    - While downstream directory trees are supported in off/on-line display of HTML files from computer harddisk and CD-ROM, the most straightforward set-up consists in keeping all files of a server node in one directory. In this case all calling commands require only the name of the called file.

    2. File Download

    - In the Martinsried CytoRelay node only file names are provided in all calling statements i.e. all files are contained in one directory. The full URL (universal relocator) information consisting of the computer address and the directory tree is appended at login from outside e.g.:
    |a href="offint1.htm"> Off-Line Internet |/a>
    is automatically reconstituted to:
    |a href="http://www.biochem.mpg.de/valet/offint1.html"> Off-Line Internet |/a>.
    (The | characters avoid interpretation of the above lines as network browser commands. They have to be replaced by < characters in real .htm files).

    - Recent Netscape 3.x and Mosaic 2.x browser versions make a distinction between .htm files for UNIX operating systems and .htm files for PC's. The PC as well as the UNIX compatible version of all Martinsried administered .htm text files and .GIF image files can be downloaded in compressed form as: MARTINS1.ZIP and: MARTINS2.ZIP

    - Decompression of these files by the PC PKUNZIP program provides the files: MARTPC1.ZIP, MARTUNI1.ZIP and MARTREAD.ME.

    - Decompression of the MARTPC1.ZIP and MARTUNI1.ZIP files into separate directories provides the PC and UNIX compatible simultaneous Off/On-Line Internet versions of the Martinsried files.

    - To prepare other files for simultaneous Off/On-Line Internet use, a DOS program ( OFFINT1) cuts unwanted local URL and directory informations from .htm or .GIF files. The program furthermore transforms .html file names into .htm file names for PC users (OFFINTPC.BAT).

    3. Local File Setup
    3.1 Single Node Setup

    - In the simplest case the: martins1.zip file is downloaded by the FTP function of the network browser into a preestablished directory e.g.: C:\INTERNET

    - Following unzipping with: PKUNZIP MARTINS1, a bookmark in the appropriate network browser directory has to be generated by the user. Its name is: OFF-LINE CytoRelay Martinsried and its calling sequence: file:///c:/internet/cytorel.htm

    - Adressing this bookmark with the network browser will produce the correct image of the CytoRelay homepage. The off-line addressable buttons will be:
    - Analytical Cellular Pathology (ACP)
    - European Society for Analytical Cellular Pathology (ESACP)
    - European Working Group on Clinical Cell Analysis - Deutsche Gesellschaft für Zytometry (DGZ)
    - MPI-Biochemie Martinsried
    - Purdue Mailbox Mirror
    - Transatlantic www-Mirrors
    - Consensus/Ring Trials
    - Internet Operation
    All other active buttons are on-line addressed, provided the network connection is active. Otherwise an error message will be generated.

    3.2 Multi-Node Setup

    - The download from multiple nodes into the above file directory may cause improper file addressing due to identical files names from different locations. One way to reduce this danger is to reserve the first three file name characters as file origine e.g. MAR = Martinsried, PUR = Purdue. In this case only five characters are left for file content explanation which may be undesired.

    - Alternatively it is easier to download the off-line files of each node into a separate directory. A master homepage file is used to address the different homepages. The Martinsried files would be placed accordingly e.g. into the subdirectory: C:\INTERNET\MARTINS prior to unzipping.

    - The bookmark of the network browser would now address the master homepage MASTER.htm file in the C:\INTERNET directory as:
    file:///c:/internet/master.htm

    - The master homepage in turn adresses e.g. the two homepages of the Martinsried node as:
    |a href="martins/cellbio.htm"> Cell Biochemistry, MPI-Biochemie, Martinsried
    |a href="martins/cytorel.htm"> CytoRelay Martinsried |/a>

    - No modifications are required for any of the downloaded .htm files in the C:\INTERNET\MARTINS subdirectory, provided that all off-line file calls contain only the file name without any leading characters like: /, ../ or: http: in the: href=" or: src=" calling statements. This is important to avoid the generation of wrong directory trees by the network browser, leading to improper off-line file adressing.

    3. Computer and Browser Setup with different Network Setup
    3.1 Off-Line Internet with On-Line Network

    Off-line Internet files are best addressed by bookmark calls. Off-line .htm and image files on hard disk are off-line addressed while on-line localizations continue to be on-line addressed under these conditions.

    3.2 Off-Line Internet without Network Card

    All network addresses in the .INI file of the network control program have to be preset to: 0.0.0.0 (e.g. in Trumpet TRUMPWSK.INI). The HomePage line in the browser's MOSAIC.INI or NETSCAPE.INI files in the: \WINDOWS directory are set to the location of the off-line MASTER.htm file location on the harddisk e.g:
    HomePage=file:///c:/internet/master.htm
    Upon calling, Mosaic and Netscape browsers immediately display the off-line: MASTER.htm file. All accessible off-line files are callable through the active buttons in the MASTER.htm file. On-line calls generate an error message which is bypassed by a mouse click.

    3.3 Off-Line Internet with an Off-Line Network Card

    In case a network card without connection to the active network is present in the computer , Mosaic browsers generate a bypassable error message while the operating system gets stuck in our hands with Netscape browsers due to a non bypassable error message.

    3.4 Conclusion

    Off/On-line Internet is best setup on either on-line network computers or on off-line network computers without network card.

    4. Literature References

    1. G.Valet, M.Valet, J.P.Robinson: Off-Line Internet: A Timesaver for sloww WWW-Sessions. Cytometry Suppl.8 105,(1996)
    2. J.P.Robinson, S.Kelley, G.Valet: CD-ROM Electronic Distribution for Cytometry. Cytometry Suppl.8 106,(1996)

  • Internet Operation
  • CytoRelay

  • Off-line Internet, a timesaver !

    Download all Martinsried cytometry pages, check the concept, follow the installation instructions (PC) and display text and graphics from your harddisk without network delay


    For problems or comments, please contact:
    G.Valet E-mail: valet@vms.biochem.mpg.de, Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany, Tel: +49/89/8578-2518, -2525, Fax: +49/89/8578-2563, INTERNET address: http://www.biochem.mpg.de/valet/cytorel.html
    Last update: Nov.11, 1996