This chapter provides an overview of SoftWindows for Unix, and describes the new features in SoftWindows version 2.0.
SoftWindows is a complete IBM-compatible PC in software. It allows Unix users to run Windows and MS-DOS applications on their workstations as if they were running on a PC.
It combines full PC compatibility with fast performance and built-in networking, so, for example, users can receive electronic mail, read PC-formatted CD-ROMs, and print PC files to a network printer, all from their Unix workstation.
SoftWindows is available for the leading RISC-based Unix workstations from Silicon Graphics and others.
SoftWindows provides integrated access to information throughout an organization by letting PC and Unix users share the same data and applications. From one workstation users can run native Unix applications, Windows and MS-DOS applications, and also use PC-based networked systems.
SoftWindows allows users to standardize on today's most popular productivity applications, such as Microsoft Office and Lotus SmartSuite on a PC, Unix, and Macintosh platforms, throughout the organization.
SoftWindows 2 provides full emulation of the Intel 80486 processor, enabling users to exploit the full functionality of current PC software.
Among the features provided by this emulation are:
The ability to run Windows in enhanced (32-bit) mode
Continued support for OLE 2.0
Multiple MS-DOS sessions
32-bit memory addressing
Support for virtual device drivers
In addition, the 486 processor emulation provides the environment required to run future versions of Windows.
The Intel 80486 is a far more complex processor than the processor emulated in SoftWindows 1. As a result, emulating the 80486 processor is also more difficult. By making major developments in its advanced compiler and translation technology, Insignia Solutions has achieved this emulation at up to 80486 performance levels.
Unlike MS-DOS applications, in which code is often executed in relatively small, tight loops, Windows applications extensively use the Windows libraries to execute standard functions. This results in frequent transfers of control and much wider use of code segments. The 486 processor emulation at the heart of SoftWindows 2 has been designed to accommodate this change through an integrated use of interpretation, dynamic compilation and static compilation of the Intel instructions.
The Intel 80486 instructions are read sequentially and translated into the host RISC instructions.
Frequently executed Intel code segments are identified and compiled into RISC code segments. The compiled segments are then cached and run directly whenever the Intel segments are executed.
Frequently used Intel code (such as portions of Windows) is optimally compiled into RISC code and built into the SoftWindows product. When this code is called, the RISC version runs directly without any interpretation or compilation overhead.
This technology, together with an in-depth understanding of the Windows source code, has resulted in a highly efficient emulation of this complex processor.
The SoftWindows technology has been designed as a cross-platform solution, to allow it to be ported to several different RISC architectures and platforms. After porting the core technology to a new architecture, SoftWindows is tuned for optimum performance.
The design of the 80486 processor emulation has evolved to encompass the performance features of today's latest RISC processors. Moreover, each version of SoftWindows exploits the best hardware and operating system features of the MIPS architecture and Silicon Graphics IRIX.
SoftWindows provides networking support as though the SoftWindows user were running their programs on PC hardware. The SoftWindows user is shielded from the complexity of running PC networking software in an emulation environment on a Unix host.
A number of solutions are built in to address the variety of networking software that may be running on a PC and the network. More than one networking protocol can be used at the same time.
SoftWindows 2 extends this network support through the implementation of a Windows Sockets (Winsock) compliant Dynamic Link Library (DLL) and the support of most major manufacturers' token ring hardware.
SoftWindows networking is based on the Open Datalink Interface (ODI) standard, which enables multiple transport protocols to be used simultaneously. Insignia Solutions' ODI-compliant network drivers communicate with the host workstation's network interface.
The diagrams on these two pages show how MS-DOS and Windows applications communicate via different network software in PC hardware and SoftWindows environments, respectively.
Winsock is a high level API for accessing TCP/IP networks from Windows applications.
Being a publicly available standard Winsock removes the need for applications to be coded for specific third party TCP/IP software implementations on the PC. It is therefore being rapidly adopted by application developers and network software vendors.
SoftWindows 2 includes a Winsock-compliant DLL which communicates directly with the TCP/IP protocol stack in the host Unix system, resulting in a more efficient implementation of Winsock. This WINSOCK.DLL is pre-installed, leaving only the application software to be configured.
SoftWindows 2 extends the support for copying and pasting between Windows applications and host Unix applications to include bitmap graphics. This enables graphics available in one environment to be used in the other. For example:
A view of a rendered model created in a Unix modeling application can be copied and pasted into a report written in Microsoft Word within SoftWindows.
Commercially available clip art from a PC format CD-ROM can be copied and pasted into a Unix application.
SoftWindows is user-configurable through menu options and dialog boxes.
SoftWindows 2 also allows a system administrator to disable the user configuration feature and to implement SoftWindows as a secure system for running one or more specific PC applications.
The security features included in the secure implementation are:
Motif menus are disabled.
Booting from floppy disks is disabled. Floppy disks may still be used for reading and writing data.
Selected keys are disabled at boot time to ensure boot sequence is always fully completed.
Selected keys are permanently disabled to prevent users from exiting to MS-DOS.
SoftWindows 2 includes tools which allow Windows and MS-DOS applications to be placed under concurrent-use license control. This is achieved through the FLEXlm license server used to license the SoftWindows application.
A PC-based license generator program enables licenses for any PC application to be generated with options for specifying start date, expiration date and number of concurrent users.
Application licensing allows you to ensure compliance with PC software licensing agreements, or as a tool for managing in-house software maintenance, where start and expiration dates can be used to ensure consistent versions across an organization.
Together with the security configuration options already described, this feature gives the administrator an extra level of control over PC software compared with that currently available on PC hardware.
SoftWindows 2 is supplied with an installation option for selecting which language version of MS-DOS and Windows to use. Language options currently supplied are English, French and German.
A CD-ROM contains the installation software and versions of SoftWindows for your Silicon Graphics workstation. Use Software Manager or “inst” to install the files from the CD-ROM.
Once the CD-ROM is mounted, on-line help is available to assist the installation procedure.
The SoftWindows installation includes complete versions of Windows and DOS for each user on your workstation.
Changes have been made to the user interface in SoftWindows 2 in response to customer feedback. These include:
Easier sizing of the Windows desktop with standard PC screen size options and control over when the user is prompted to resize the Windows Desktop.
Easier configuration of Unix directories as PC network drives.
Menu bar instructions on how to restore the host mouse pointer when the MS-DOS mouse is used.
On-line help buttons in all configuration dialog boxes, in addition to the Help function accessed from the main menu.
An option to save the current configuration as the default without quitting SoftWindows.
A configuration file option to disable the read-only hard disk warning.