Intergraph Corporation
InterAct 32C Workstation

    The Intergraph Corporation InterAct 32C in my collection is an example of a mid- to late- 1980s CADD (Computer Assisted Design and Draughting) workstation. This example sports a final test and checkout label bearing the date of 2/September/1987. The machine, shortly after its introduction, won several industrial design awards for ergonomics. Sadly, Intergraph seems deliberately intent on seeing the architecture go "extinct" inasmuch as they categorically refuse to release any technical documentation on the hardware.

    This particular machine utilises the Clipper microcomputer chipset which sports a 32 bit wide word with a flat 32 bit address space. Depending on the exact CLIX (CLipper unIX) engine installed, main memory is either six Mb or sixteen Mb in size, 5 or 9 MIPS (Million Instructions Per Second) in speed. I have a pair of CLIX engines; one uses the original Fairchild design known as C-100, the other came out after Intergraph bought the Clipper design project from Fairchild and is known as the C-300. The C-300 here is derated from its design speed of 10 MIPS to 9 MIPS for this particular application.

    Mainstore capacity also varies depending on the CLIX engine currently installed. The basic C-100 engine (which was the stock brains of this device) contained 6 Mb; the C-300 board I posses, contains 16 Mb. Both boards were non-expandable; the 32C line did not support external memory subsystems.

    Basic disk storage as delivered from the manufacturer in the 1980s was 80 Mb on a single SCSI (Small Computer Systems Interface) Winchester disk drive. It has since been expanded; as is the case with most systems supporting the SCSI standard, virtually any disk device may be connected without the need for writing new drivers. A single 5.25" floppy drive was standard equipment on this workstation.

    The dual 19" (analogue) colour monitors each have a resolution of 1184x884 pixels and a palette of 32 simultaneous from 16,777,216 colours (5 bits per pixel indexing into a 24 bit colour lookup table).

    The operating system used on this machine is known as CLIX and is a derivative of AT&T UNIX with various Berkeley facilities added (such as sockets). While it's a full multitasking OS, CLIX is not multi-threaded in the same manner as newer OSs. The basic windowing system, taking advantage of the dual screens, is known as Environ V. An X-window system is also operative on this machine.

    The "desk" in front of the machine is an active digitising area, using electromagnetic locating mechanisms to determine the exact position on the pointing device (a coil) on the table. Optionally, a "floating menu" was provided, allowing two separate frames of reference on the same active surface. This example includes the "floating menu".

    Six 10.5 x 9.5 inch PC boards are used to implement the basic machine: the CLIX engine (with the Clipper microprocessor and mainstore), an I/O Processor (embodying disk, network, serial line, and various peripheral control), the digitiser controller (handling the task of dealing with the active table), a ROP (Raster Operations Processor, controlling drawing operations into raster memory), and a pair of Frame Buffers (one for each screen).

[ Museum Lobby ] [ Museum Catalogue ] [ Carl's Homepage ]

Comments to: crfriend@rcsri.org