Is There A Blackbird in Your Future?

Traveling Software’s Blackbird Could Set the Standard

In our June special issue (Vol. 1, No. 3), we briefly mentioned the strategic technology agreement between the pen-centric tool developers at Slate Corp. and the portable computer wizards at Traveling Software (TS) in Bothell, WA. At the time, we speculated that file transfer or data communication software was at the heart of the agreement.

Since then, we’ve learned more from TS representatives about the company’s communications toolset and it extends far beyond the bounds of file transfer and pen-based, mobile computing. In fact, the software, named Blackbird, may be one of the most ambitious and potentially most powerful commercial communications libraries available for PC software development. Using the Blackbird library, programmers will be able to build applications that have sophisticated, robust communications capabilities for platforms ranging from handheld PCs to mainframes.

Blackbird, which has been under development for 2-1/2 years, is a powerful, high-performance communications engine modeled after the International Standards Organization (ISO) Open Systems Interconnect (OSI) Reference Model, implementing the physical, datalink, network, and transport ISO layers. The OSI Reference Model itself is an open system approach for communication interfaces that provides a standard set of rules and procedures. Adhering to this model reduces the cost of system development, procurement, support, and maintenance by eliminating the need to develop, debug, and maintain custom interfaces. (For more information on the OSI Model, see “Designing an OSI Test Bed,” by Kenneth Crocker and Michael Thompson, Dr. Dobb’s Journal, December 1990.)

Blackbird Is Feature Rich

The TS communications library, which is platform and operating systems independent, provides multiple drivers at the physical layer; serial, parallel, and cellular are currently supported and ISDN and RF wireless drivers can easily be added, according to Traveling Software representatives. The engine operates at over 200K baud using the standard PC serial port (7 wire) or at 115.2K baud (3 wire). It can also operate at over 500K baud using standard PC printer ports.

The library supports automatic connection with available equipment, notifying the application of available services. When connections are broken, the link is automatically re-established without system or application restart.

Blackbird also supports multiple virtual connections that can be shared over one physical connection. For instance, file transfer and printer redirection can happen concurrently since associated data packets can be intermixed. The number of sessions is limited only by CPU power. Additionally, the library provides for interpacket notification, a mechanism whereby the application is notified after every packet exchange.

Patented Technology; Already Implemented

TS has applied for several patents associated with Blackbird, among them a patent for a unique bi-directional, high-speed, 8-bit data transfer technique, another for a real-time, CPU-driven, on-the-fly compression/decompression routine that runs up to 115.2K baud off a serial port, and yet another for a realtime error-correction trick that concurrently sends data and checks for errors for maximum throughput.

Traveling Software obviously has confidence in Blackbird. The company has already implemented the library in at least two current products of its own—the recently released WinConnect (a Windows 3 linking utility that permits disk sharing between two computers within the Windows environment) and DOS Connect (connectivity utilities that provide file access between Hewlett-Packard’s HP 95LX palmtop computer and desktop PCs). Other developers, presumably Slate among them, are also at work developing software built around Blackbird.

The library, which will be distributed as object code and has its own Software Developers’ Kit, will be available in the fall of 1991. Licensing details will be decided at that time.

Into the Future

While we haven’t had hands-on experience with Blackbird, several software developers who have worked with early versions of Blackbird tell us that they are impressed with the power and comprehensive specifications of the product. We think Traveling Software may be on to something big. The company has traditionally anticipated and successfully delivered on the requirements of portable computing. And pen-based systems will provide the ultimate test for fast, reliable, and flexible communications software. Blackbird looks like a big jump in the right direction.

Contact:
Traveling Software
18702 N. Creek Pky.
Bothell, WA 98011-9916
206-483-8088