Welcome to Ram
Meenakshisundaram's Transputer Home Page
sequential computers are
approaching a fundamental physical
limit on their potential power. Such a limit is
the speed of light
Helios is a micro kernel operating system for
embedded and multiprocessor systems. The operating system is modular in design
and can scale from an embedded runtime executive up to a fully distributed
operating system. It has adopted many internationally recognised standards:
POSIX, BSD, X, TCP/IP and Windows. Existing programs can thus be ported to
Helios and remain easy to maintain.
A UNIX like csh supports a variety of development and monitoring tools
for the target hardware. A host support server (IOServer) provides disk,
keyboard, networking, screen and peripheral services to target application
programs. This allows services normally found only on the host development
computer to be fully accessible by target programs as if they were local
services. The services conform to the Helios server specification, which means
the services can be transferred transparently from the host to the target
without modification to the target application. For example, networking
applications can be developed using host ethernet facilities on standard
development boards while target hardware is being designed.
Distributed versions of Helios feature a comprehensive suite of utilities
and libraries for parallel/distributed computing. Helios provides several models
of parallel computation, each suited to different parallel problems.
The smallest Helios module is the kernel. It supports memory management,
multi tasking, synchronisation primitive and interrupt handling. Further modules
can be added to the kernel to build a Helios nucleus, these can include code
loader, task manager, and message passing. Libraries and device drivers may also
be built into the nucleus.
Real-time versions of Helios provide fully deterministic response times
for all operations. The kernel implements a multi-level priority based real-time
scheduler. The multitasking time slicing quantum is user programmable and can be
turned off if desired. Embedded support includes utilities for splitting and
building custom nuclei and ROM file servers.
- ANSI C, C++,
- Multi language compiler driver
- POSIX 1008.1 library
- BSD 4.3 library
- Server library
- Vector Library
- Shared and scanned libraries
- Over 100 Unix commands
- Development utilities, make, touch, grep etc.
- On-line help
- Emacs editor
- Shell similar to csh, file name completion, history, variables...
- Helios Source
- Comprehensive 600 page user manual
- Two volume encyclopedia
- Getting Started guide
- Editor Manual
- Server Library
- Host IOServer support; RS232, Centronics, Clock, Ethernet ...
- Ram disk
- Public domain software
- Multiple over-laid windows
- Pipe and FIFO servers
- Memory resident include disk server (source code)
- Automatic process distribution servers
- Device driver support
- Helios TCP/IP
- X Window, VGA
Graphics, OSF Motif, SUN OpenLook, Solaris, Windows or PC Text
- Fault tolerant adaptive message passing
- Multiplexed Virtual channels
- BSD Socket communications
- Fast memory control
- Capability based protection
- Signal handling
- Multi user support via RS232, Ethernet, or link/port connection
- Processor protection between users
- Network administration commands
- Link/port configuration drivers
- Network fault monitoring and individual reboot.
- Resource Management library
- CDL parallel description language
- Farming library
- Raw link/port access
The Helios PC IOServer has two windowing
systems: PC text overlaid windows and Microsoft Windows support. The Windows
IOServer is compatible with the Helios Windows Graphics Library. The IOServer
also includes an int60 trap handler which allows PC TSRs to be called directly
from target hardware. Connection of target hardware to Helios can be through
RS232, Parallel, PC Bus, Link, or ComPort. Contact Perihelion
for a list of supported boards.
Helios SUN is a port to Sun Micro System
workstations. Supported workstations include Sun 3 and 4 machines. Helios SUN
includes IOServer internet services which merge the socket domain of the host
computer to the Helios target. This means that both host and target programs can
easily communicate to each other via sockets. A practical example would be a
Helios X client program directly calling the host XServer. Helios SUN includes
Ethernet I software, enabling remote access to and from networked resources. A
network daemon called hydra allows remote access of target hardware from
anywhere in the network. Helios SUN supports both SUN View and Open Window
interfaces. Helios SUN includes support for a wide range of SBUS and VME boards.
Contact Perihelion for a list of supported boards.
This page is copyright ©1996, Perihelion