User:Ferdilouw/Legacy printing

Printing from legacy systems is an attempt to reconcile old (1970-1990) software with current (2008) printing technology.

Software that was designed for dot-matrix printing on fan-fold paper doesn't perform to what people expect from laser printers. The older printers give more problems and are more expensive. Mainframe systems or unix servers are often in need of improved printing performance but due to reasons mentioned at legacy system, alternative measures need to be investigated.

Overview

Legacy systems are considered to be potentially problematic. For example, see Jesus Bisbal et al., 1999^[1] at the height of the Y2K FUD. Naturely it is not all FUD and a lot can be done to improve the situation.

Legacy systems often print on obsolete (and usually slow) hardware, and sometimes spare parts for such printers become increasingly difficult to obtain. They are less reliable and hard to maintain, improve and expand. Integration with newer systems may also be difficult they use completely different technologies.

However, many of these systems do still meet the basic needs of the organization. The systems to handle customers' accounts in banks are one example. Therefore the organization cannot afford to stop them and yet some cannot afford to update them.

Solutions

ASA/FORTRAN control characters If you want nice formatted reports from your application, t There are a number of ways to achieve this.

Templates

With templates you can add forms and graphics like logos to your printed reports.

Formatting

The original method (dating from DOS days) was to send printer escape sequences as part of your data.

methods that would allow these sequences to pass through Windows without being touched by the Windows printer drivers. Printer escape sequences are limited in the amount of formatting they can supply and are dependent on the model of the physical printer being used.

Paperless printing (electronic delivery)

The move towards a paperless office creates new requirements. Documents delivered by e-mail are preferable to paper copies. Some reports from legacy systems are only required to be stored in a new format for third party applications to extract information from them.

4. The File printing option allows you to use any other (external third party) program to process print jobs. E.g. Call Word to do a mail merge with the data.

Mail Merge was introduced as a method to give you all the advances of RTF without the need to learn RTF control words and editing pre- and postamble files. This is the easiest method to specify the full formatting of a report using a PC word processor. Two merge methods are available. The generic merge method requires no programming. Every line of printer data will replace one field in the template document. The template document is specified on the PC. Each line of data is restricted to the same text format.

RTF

1. We recommend the RTF method because of the wide acceptance in multiple products of the RTF standard. RTF allows the most formatting instructions and should have a long open upgrade path to the future. The development of the application to insert the RTF data into the data stream is more complicated than the other methods. RTF printing became popular for users of Inet3270 where the Natural file transfer and commands are used to give fast printouts without going through a print spooler. Developments have been done on IBM mainframes and Object Star database servers.

A summary of some basic RTF control words as well as links to complete RTF manuals on the Internet are given at RTF notes for developers of formatted printing.

The other method, advanced merge, is now (January 2005) under construction and will allow full programmable control from your server/mainframe application to specify various templates and fields as required. The template name and field names may be embedded in the data sent from your application. Additional logic may be built into a script to split a single line into multiple fields. Learn how to use it at Merge printing for developers of formatted printing.

Propriety solutions

3. The Inet Format was introduced as an easy conversion from using printer escape sequences to using printer independent instructions. The Inet Format supplies many more facilities than available in traditional printer escape sequences but not all the bells and whistles possible in RTF. Inet Format is a proprietary standard, but is so simple that it can be used in some applications as one of the user defined printer tables. See Inet Format escape sequences for developers of formatted printing for a description of the Inet Format device independent commands and sequences supported.

Improvements on legacy software systems

Printing improvements is also problematic since legacy software systems adds no formatting instructions or use protocols that are not usable in modern PC/Windows printers. E.g.: On ribbon printers (dot-matrix and line printers) the only method to get bold text was to re=print the same text a number of times on the same place on the paper. This method has no effect on laser printers. The other option was to include escape sequences (propriety printer instructions) in the data stream. Newer printers and Windows don't support these instructions. However an intelligent print server can intercept the data and translate it to a more modern instruction. Winet is a commercial print server product with some of these functions. Some development work went into Rich Text Format (RTF) or PostScript that is created in the legacy application and then interpreted at a PC before being printed.

Virtualization technology allows for a resurgence of modern software applications entering legacy mode. As system complexity and software costs increase, many computing users are keeping their current systems permanently in legacy mode.

Brownfield architecture

brownfield.^[2]

Alternative view

There is an alternate point of view — growing since the "Dot Com" bubble burst in 1999 — that legacy systems are simply (and only) computer systems that are both installed and working. In other words, the term is not at all pejorative — quite the opposite. Perhaps the term "legacy" is only an effort by computer industry salesmen to generate artificial churn in order to encourage purchase of unneeded technology. Bjarne Stroustrup, creator of the C++ language, addressed this issue succinctly:

"Legacy code" often differs from its suggested alternative by actually working and scaling.
— Bjarne Stroustrup

IT analysts estimate that the cost to replace business logic is about five times that of reuse, and that's not counting the risks involved in wholesale replacement. Shareholders and managers are increasingly asking, "Why are we spending so much money on new technology with so little to show for it?" Ideally businesses would never have to rewrite most core business logic. After all, debits must equal credits — they always have, and they always will. Businesses and governments are also recoiling at well-publicized system failures and security breaches that all too commonly arrive with new software — failures which are utterly catastrophic in many cases. (A regional airline fired its CEO due to the failure of an antiquated legacy crew scheduling system during Christmas, 2004, for example.^[3]) There's also a growing backlash against large, packaged software products (SAP, Oracle, PeopleSoft, and others) which were oversold and in some cases have proven too costly, inflexible, and poorly matched to business needs.

Increasingly the IT industry is responding to these understandable business concerns. "Legacy modernization" and "legacy transformation" are now popular terms, and they mean reusing and refactoring existing, core business logic by providing new user interfaces (typically Web interfaces) sometimes through the use of techniques such as screen scraping and service-enabled access (e.g., through Web services). These techniques allow organisations to understand their existing code assets (using discovery tools), provide new user and application interfaces to existing code, improve workflow, contain costs, minimize risk, and enjoy classic qualities of service (near 100% uptime, security, scalability, etc.).^{[citation needed]} Technology companies involved in "enterprise transformation" are growing and profiting by what many people feel is a more rational approach toward legacy systems.^{[citation needed]}

The reexamination of attitudes toward legacy systems is also inviting more reflection on what makes legacy systems as durable as they are. Technologists are relearning the fact that sound architecture, practiced up front, helps businesses avoid costly and risky rewrites in the first place. The most common legacy systems tend to be those which embraced well-known IT architectural principles, with careful planning and strict methodology during implementation. Poorly designed systems often don't last. Thus, many organisations are rediscovering not only the value in the legacy systems themselves but also their philosophical underpinnings.

References

^ [1] Legacy information systems: issues and directions. Bisbal, J. Lawless, D. Bing Wu Grimson, J.; IEEE Software; Sep/Oct 1999; Volume: 16, Issue: 5, p.: 103-111 ISSN: 0740-7459
^ Definition of greenfield and brownfield deployment
^ Comair's Chirstmas Disaster: Bound To Fail - CIO.com - Business Technology Leadership