VAXELN

VAXELN Version 2.2 is a Realtime Software Toolkit designed for developing efficient, low-overhead applications that run on dedicated VAX and MicroVAX systems. It operates as a layered product on a VMS or MicroVMS host system, leveraging its development resources to produce highly optimized execution code for the target environment.

Key features of the VAXELN Toolkit include:

• Optimized Compilers: An extended EPascal compiler specifically optimized for realtime code, alongside runtime libraries for EPascal, C, and FORTRAN-77. Optional Ada, C, and FORTRAN compilers are also available.
• Realtime Kernel: A simple, small kernel that efficiently controls shared system resources, supporting multitasking and multiprogramming with preemptive priority-based scheduling.
• Development Tools: A powerful system builder combines program images, the kernel, and runtime routines into a single, compact VAXELN system image. It also features a robust VAXELN Debugger for interactive local or remote (over Ethernet) debugging of both modules and entire applications.
• Connectivity & Device Support: Provides transparent network communications via Ethernet-based DECnet (DAP) for distributed applications and downline loading. It includes device drivers for a wide range of Q-bus and UNIBUS devices, offering file storage capabilities through the optional VAXELN File Service.
• Database Support: The optional Rdb/ELN component enables the development of realtime applications based on a relational database.

VAXELN applications are well-suited for scenarios such as factory automation, dedicated CAD/CAM workstations, and large-scale data collection systems. They can function as standalone units or integrate into an Ethernet Local Area Network (LAN) with VAX/VMS nodes. The toolkit has specific hardware requirements for both the VAX/MicroVAX host development system and the dedicated target system.