HLLAPI Development Center

HLLAPI and it's variants (WinHLLAPI/EHLLAPI/IHLLAPI) are the de facto standard for programmatic access to terminal sessions through terminal emulators across many platforms. Seemingly straight forward, many HLLAPI projects break down under production loads because of HLLAPI's complex interaction with the host, emulator and application.

Conklin Systems knows HLLAPI literally from the inside out. We wrote the WinHLLAPI implementations for the PCLINK family of terminal emulators, and in the process studied and implemented every function, every parameter, and every bit of the WinHLLAPI API for both 16-bit and 32-bit Windows operating systems.

Conklin Systems has supported dozens of major developers using the WinHLLAPI API, and we know the tips, tricks, hacks and workarounds they've resorted to to support the often broken HLLAPI implementations on the street. We've helped the likes of Harland/CFI ProServices, Decision Support, BranchConnect and Easy Systems all get up and running in production banking environments.

We'll help you with:

We offer assistance to HLLAPI developers, HLLAPI API users, and people wanting to develop new HLLAPI-based applications. End-users should contact their HLLAPI product vendor for assistance first, or their terminal emulation vendor if they're having connectivity problems in general. However, if you are an end user with a critical HLLAPI installation and need an independent, expert opinion to cut through the blame game and get results, feel free to contact us.

Contact us today to get your project moving! Thousands of users rely on our HLLAPI code daily. You can too. For full contact information, see the bottom of the page.

Conklin Systems provides vendor-neutral support for HLLAPI. Regardless of your platform, emulator, or application, we're here to help.


Looking for world class HLLAPI access to legacy Unisys environments? We recommend Virtual Soft's family of Unisys T-27 emulation products, including PCLink! Ultralite and PCLink 32, for rock solid WinHLLAPI, Poll/Select and TCP/IP stacks. We ought to know... we wrote them.