Attention was drawn to PC-LAN systems and business UNIX machines with the advent of cheaper, more powerful workstations and personal computers and the widespread adoption of LANs. This was the first wave of the open systems era.
Mitsubishi Electric developed the DP-UX operating system for the RX7000 series of Solutions Servers that were announced in July 1994. DP-UX relied on the DPS 10’s architecture but featured much better connectivity with personal computers and UNIX machines and more powerful functions that handled various de facto standards.
Although dedicated terminals that connected to office computers with coaxial cables were still in the majority, corporations were increasingly turning to the ap-BIND terminal emulator because it allowed personal computers to emulate dedicated terminals.
DP-UX, between 1994 and 1995, offered the following open-system connectivity functions.
- (1) Standardization of TCP/IP networks
- DP-UX’s standard network protocol was TCP/IP, and the operating system came with many networking functions, such as ftp, rsh (remote shell), NFS (network file system), a WWW browser, and an SMTP mail server.
- (2) Open terminal operating environments
- By supporting job control environments based on Windows’ graphical user interface and terminal emulators based on telnet, DP-UX made it possible to use Windows and Macintosh computers as office computer terminals.
- (3) Open databases
- DP-UX supported the Open Database Access Mechanism of the Open Database Connectivity (ODBC) interface and HYPERGSAM of Btrieve interface so that DP-UX databases could be accessed from personal computer software programs.
- (4) Open development environments
- DP-UX supported three development environments: HYPERPRODUCE, a Visual Basic platform for developing client-server applications; a POSIX-compliant C-language development environment; and COBOL II, a COBOL language compliant with ANSI standards.
- DP-UX B00 Version
- Announced in 1995, the RX7000 models D20 and E20 were all-in-one client-server machines. The CPU and memory for low-end office computers were mounted on a single board (which was named the “DP-UX compatible engine” in 1996), and the board was incorporated into hardware with an Intel architecture. Mitsubishi Electric developed the DP-UX B00 version to run on the D20 and E20 models. The DP-UX operating system and applications ran on the DP-UX compatible engine, but all I/O processes issued from DP-UX to disks, LANs, tapes, and other I/O devices were virtualized and passed to Windows NT service programs. The I/O service programs converted the DP-UX I/O processing to Windows NT I/O processing and carried out the I/O processing with the actual hardware. The D20 and E20 won favor with the market as small systems, because they were all-in-one client-server office computers that were at the same time an office server that ran applications and a client personal computer that ran a terminal emulator.