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EHLLAPI, or the Extended High Level Language Application Programming Interface, was introduced soon after the introduction of the IBM 3270PC, which was a special personal computer that integrated a 3270 COAX adapter and a specialized keyboard. The 3270PC eased the transition between a traditional terminal and a Personal Computer for those users looking to merge the functionality of the two.
HLLAPI followed the use of 8086 Assembler as a means to integrate to the screen sessions active in the 3270 emulation portion of the device and featured accessibility from Compiled BASIC (which at the time was "it" for "High Level Languages" on the PC).
EHLLAPI adds the "Extended" to the HLLAPI API with a few additional synchronization and convenience functions. So, with just a few additions to the API a whole new acronym was introduced and today we treat both HLLAPI and EHLLAPI as one and the same, obsolete relics!
EHLLAPI is, unfortunately, not that "high level" in that each and every operation needs to be performed using low-level parameters that have little resemblance to high-level data types. In fact, the parameters used in EHLLAPI are closer to machine registers for a specialized emulation integration hardware than they are to anything like a true API.
The use of EHLLAPI as a means of integration between the programs in the PC and the emulation sessions continued as the PC evolved, and multiple hardware/software developers introduced their own emulation solutions to the market. This was unfortunate for those needing to use the API, as the strict and limited parameter approach meant long and arduous coding, test and debugging cycles. In addition to the long development cycle, the obtuse nature of the API makes modifications very difficult. Due to the typical high change rate of screen-based applications this high maintenance cost added to developer frustration over the use of EHLLAPI in implementing screen integration projects.
Luckily for developers today, the use of EHLLAPI is no longer required, as vendors such as Inventu and Flynet have introduced very high level integration approaches (as well as supporting tools and runtime administration components). With these new, more productive and easily managed solutions, EHLLAPI can join the 3270PC in the PC Museum as a relic of the past.
Inventu Corporation
Inventu provides our Customers with software and services to implement new applications that support business initiatives. Inventu concentrates on using, replacing and renewing existing (legacy) applications using our own product, Screensurfer and our Partner's product, Flynet Viewer.
Screensurfer
Screensurfer is an All-in-one host screen-to-Web application server that runs on Windows servers such as Windows 2000 and Windows Server 2003. Screensurfer is self-contained; no other products or development tools are needed to implement a new web-to-host application.
With an HTML-based tag language (Surferscript) which is very similar to Coldfusion CFML, Screensurfer provides very high productivity when converting existing 3270, 5250 and VT100 screens into HTML pages.
Screensurfer's IDE, the Express Editor and Debugger, provides an integrated editing and step-trace debugger for a solid editing and development environment that any developer can appreciate.
Flynet Viewer
Flynet Viewer provides "everything you need" and "nothing you don't want" for screen interfacing by development teams utilizing Microsoft IDE environments such as Visual Studio .NET, Visual Basic and Visual Interdev.
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