| About McIDAS McIDAS-V McIDAS-Lite OpenADDE | ||||
A Brief History of McIDASThe Space Science and Engineering Center (SSEC) at the University of Wisconsin-Madison has actively developed McIDAS (Man computer Interactive Data Access System) since 1973. McIDAS consists of over one and one-half million lines of code contained in nearly four thousand modules. The system evolved through four distinct generations and a fifth has been proposed. The first generation McIDAS was a single-user system based on a Harris/5 computer. It provided animation, display and analysis of the geostationary meteorological satellites. During the initial years, radar, meteorological observations and forecasts were added to the system. The second generation McIDAS was implemented in 1978, using several Harris/6 computers networked with high speed communications. System functionality was distributed with database building and management processes physically separated from applications processing. This provided a centralized real-time database of satellite imagery and observational weather data. The high speed network provided rapid access to the database, spurring significant growth of the user community. At its peak, this McIDAS network at SSEC had eight computers with 12 interactive workstations. The third generation McIDAS returned to the single-computer architecture using an IBM 4341/81 mainframe CPU running the MVS operating system. In 1984, SSEC initiated the PC-McIDAS workstation which placed an IBM PC/AT between the mainframe and workstation to off-load some mainframe processing and improve the user interface. With more CPU cycles available on the mainframe, its role improved as a database manager and ingest system. With a variety of mainframe applications working on the PC, users could disconnect communications from the mainframe and operate in a stand-alone environment. In 1988, with the availability of a multiprocessing operating system, PC-McIDAS was replaced with McIDAS-OS2 running the IBM OS/2 operating system on the IBM PS/2 interface. McIDAS-OS2 contained the major suite of McIDAS-MVS applications. Four OS/2-based workstation configurations were developed: a high-end WIDE WORD Workstation (WWW), an SSEC Display Adapter (SDA) workstation, the VGA display, and the Presentation Manager display. The fourth generation, with the release of McIDAS-X in April 1992, moved McIDAS to the Unix environment. It returned McIDAS to a distributed architecture where flexibility and adherence to standards, such as POSIX, are prominent characteristics. Variability in data formats, supported platforms, and user interfaces are designed into the current system. In December 1996, the IBM mainframe system was decommissioned and support for McIDAS-MVS ended in 1997. A fifth generation McIDAS is undergoing preliminary investigation. It involves a plan to transition McIDAS-X to a Java-based environment. The new system will likely be based on SSEC's VisAD package. Other Resources: |
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