Financial (Netsol®)

Success stories

Netsol

Feb 10, 2023

VAX VMS / OpenVMS to Linux/Windows
Basic:
800,000
Lines
RMS: 350 files
DCL: 224,000 lines, SMG: 620 screens

Simply stated, this company improves the operational productivity of leading leasing companies throughout the world through innovative use of technology. Until 1991 these solutions were only available on Digital Equipment Corporation (DEC) VAX platforms running the VMS / OpenVMS operating system.

In 1991, this ISV faced a marketplace that was less than accepting of proprietary systems such as DEC's VMS / OpenVMS Alpha VMS / OpenVMS They asked Sector7 to provide consulting services to evaluate the feasibility and cost of migrating their core application to Linux technology that would provide market acceptance.

Sector7 has a five-step blueprint process for moving applications from VMS / OpenVMS to Linux. The first step was an assessment. During the assessment Sector7 performed a situational analysis. The POS application was developed using DCL, FMS, RMS, and BASIC. DEC Command Language (DCL) is the control language for VMS / OpenVMS DCL is very powerful and users can write simple programs in it. Forms Management System (FMS) allows the programmer to create forms on a VT terminal and display and accept data from the user program. Record Management System (RMS) is a file system manager integrated with the VMS operating system. RMS handles indexed, relative, and sequential files. Indexed and sequential can have fixed and variable length records.

Subsequent to the situational analysis Sector7 worked with the client company to develop a migration approach to reduce TCO. Sector7 can provide solutions ranging from low-risk migration to completely re-engineered applications using Business Logic Extraction (BLE) methodologies. Migration requires making the minimum changes necessary to make the code function on the new system. This is usually the fastest way to get the code up and running on the new system. Issues such as text translation, non-portable code, and hardware differences are addressed. This type of port is very low risk and it is possible to have follow-on work to improve design and performance efficiencies. It is low risk as long as adequate time is spent planning the changes. Re-engineering using BLE requires extracting the business logic from the code to take full advantage of the features of the new system, reusing code where possible, and rewriting it where necessary. This process makes better use of the system features and usually results in better code. Often BLE is selected when organizations have set specific product standards.

The solution selected was a migration. BASIC was ported to C using Sector7's VX/BASIC product. VX/BASIC can analyze and convert VAX BASIC to the C language. For RMS, the Sector7 product VX/RMS was selected. VX/RMS is an implementation of DEC's VMS RMS system for Linux. VX/RMS allows VMS programs which access RMS directly to function without change. All VMS file types and access modes are supported. Support for relative, sequential and block mode files is supplied by direct access to the Linux or NT file system. For DCL, the Sector7 VX/DCL product was selected. VX/DCL is an implementation of DEC's VMS Digital Command Language for Linux. VX/DCL allows applications to use all of the VMS commands, which are so familiar on Windows NT or Linux systems. All of the existing command scripts (.COM files) will run on the new platform. For FMS, Sector7 VX/FMS product was selected. VX/FMS is a faithful replacement for the VMS FMS library. It provides the same APIs to applications and uses the forms definition files used by FMS. The project was completed in six months.

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