This is an article I wrote several years ago that may be of interest to the ClearPath community.
When the first ClearPath NX server was shipped, the computing world as we know it changed. Such a bold statement surely requires an explanation. While most of us working with Unisys technology know better, the rest of the world considers Unisys simply a mainframe vendor. Even with their marketing conversion into a services company, the core computing line of Unisys is what makes those services possible. The A-Series, 2200, and UNIX systems all contribute to a terrific line of systems capable of integration into any business. While these systems are no secret to those of us in the industry, the rest of the airline-magazine reading public is infatuated with conversions to UNIX and other “client-server” platforms. With the advent of ClearPath, mainframe integration with “industry-standard” operating systems has never been higher.
A Match Made in Redmond
Since the inception of Windows NT, Microsoft has positioned it as an answer to the business application, print, and file server market. Obviously, the market share achieved by Novell’s NetWare product was an attractive target for Microsoft. With the invasion of Windows NT into the corporate IS departments previously dominated by NetWare, Microsoft seems to be wining this battle. Of course, this still leaves the question of what to do with the mainframe. Most IS departments have at least one advocate for replacing the mainframe with PC file servers or UNIX systems. I recall an individual that wanted to replace a four processor Unisys A-19 system with 60 Novell file servers and PC application software. While this approach may seem attractive to non-mainframe people, in reality, it’s been proven to be both more costly and less efficient to rid the company of the mainframes. Of course, it is not without some benefit to utilize an application or file server as part of a larger data processing system. These products can be symbiotically joined to capitalize on each others strengths and minimize each others weaknesses. Historically, however; this approach has been littered with broken vendor promises and difficult, if not impossible, hardware and software combinations. This is where ClearPath comes into the equation. With the advent of the Unisys ClearPath, an IS organization can make data and applications on both the A Series and Windows NT available to the entire organization and the entire world! But, before we embark on this grand day out, perhaps some first hand observations about the components of ClearPath are in order.
The Sum of the Parts…
As most Unisys professionals already know, the NX version of ClearPath is simply an A-Series (“the mainframe”) and a Windows NT computer in the same box. Included within the same cabinet as the A-Series and the Windows NT PC is an Ethernet switch to allow central connection of network devices in both systems to a common point. Also included in the box is a UNIX system. The UNIX system is only for maintenance administration of the mainframe side. Since the units are in the same box, I have noticed that some are under the impression that the systems are dependent upon one another for certain things. In reality, any connections between the mainframe side and the NT side could also be from across the world. There is no software on either side that requires the computers be in the same cabinet. That being said, then why are the units in the same box? Simply put, being in the same cabinet adds the ability to interconnect the Windows NT system to the mainframe via a higher speed connection than 10 megabit Ethernet.
Software Makes Hardware Work
The truly magical part of ClearPath is the A-Series software. Specifically, the way in which it presents itself as an NT server. This software, called NX Services, make the A-Series appear to the Windows network as a Windows NT print and file server. Any printer to which the A-Series can print can also be accessed by any computer on the Windows NT network. This means that if you have a high-speed printer connected to the A-Series, a PC connected to the A-Series can print to the printer just as if it was physically connected to the PC. This model works for file access as well. Files on the A-Series can be accessed by Windows and UNIX systems on the network. In Windows terminology, this act of central network access to server resources is known as sharing. No longer do you need to run a file transfer process to move files between the mainframe and the PC. Of course, since mainframe disk is considerably more expensive than PC disk (although it is the same disk), it would be silly to store all PC files on the mainframe. The most efficient use of this technology is for file sharing applications between the mainframe and the PC. Whenever file sharing is an option, security is always a concern. As with any A-Series file access, the security is controlled by the usercode/password combination supplied to the software. Shared A-Series devices such as CD-ROMs and printers can be protected in the same manner. Another available resource of NX Services is the application interfaces. Now that the files and printers are shared with the help of ClearPath, the next step is to “open up” the applications. While interfacing to applications is not as transparent as file or printer sharing, it is only minimally more difficult. Basically, one writes an application using standard TCP/IP programming methods which the ClearPath software then interfaces to a COMS station on the mainframe. This allows external interfaces to legacy applications without modification to the existing A-Series programs. While this method of integration has been available on the A-Series for several years from third-party vendors, only with the ClearPath system does Unisys provide a direct interface into COMS from external TCP/IP systems.
Administration
Besides file, print, and application integration, ClearPath also excels in the area of system administration. In order to setup file and printer sharing, as well as any application interfaces, a graphical, windows-based program runs on the NT server to administer these items. This program, the Admin Center, normally runs on the NT server collocated to the mainframe side. There is, however, no requirement that this be the case. With the correct Windows NT network security established, a workstation anywhere in the world can administer the NX/Services on the mainframe. Additional Windows administration tools supplied are the Task Center and the User Center. The Task Center allows system console monitoring including all operator display terminal (ODT) commands normally used by operations personnel. The User Center allows administration of mainframe user information from a Windows system anywhere on the network. Of course, proper security is again required and enforced. Also, these packages are not simply text-based screen images running on a Windows workstation. These applications take full advantage of Windows features including list-boxes, radio buttons and check boxes.
The Whole Package
The items discussed so far are already worth the price of admission to the ClearPath show. Some notable items included with the base ClearPath NX systems are LPR/LPD printing, TransIT/ODBC and a Web server. LPR/LPD printing allows UNIX systems to print to the A-Series printers and vice-versa. TransIT/ODBC allows PC access of a DMS II database on the mainframe. A 4-user license of TransIT/ODBC is included mainly for development and small-scale production purposes. The web server allows serving of both static and dynamic web pages directly from the mainframe. From the PC side, several items have been added as well. We have already discussed the User Center and Task Center, but also available is a terminal emulator. This emulator, called NX/View, was originally supplied free with the system, but due to previous licensing agreements is now offered for sale at a very reasonable cost. NX/View interfaces directly to the TCP/IP software on the mainframe so InfoConnect is not required. While many of the “new” interfaces available on ClearPath have been available from various third-party vendors, they were not available from a single source and except for the comparatively minimal emulator licensing fee for NX/View, they are included with the base price of the system.
Summary
With the promulgation of ClearPath, Unisys and the A-Series have turned a new corner. No longer will true platform integration simply be a marketing term or a “hodgepodge” of distinct components made to work together. No longer can the idea of a closed proprietary system that will not work with other hardware or software be propagated. With ClearPath, the mainframe will continue to be a critical focus in the corporate IS picture for many years to come.