The Ranyan model 68SUM Unibus co-processor board, available from Arrow Computer Systems Ltd, Epsom, Surrey, offers high speed computation at anything up to double the rate of a DEC PDP-11 or VAX-11/7XX series computer. The 68SUM board, which uses a Motorola 68020 central processor and 68881 floating point co-processor, includes 2Mb of dynamic RAM and is packaged on a single hex board. The board is designed, by way of its VAX-like processing powers, to take some of the strain off the host machine, particularly in computation-intensive applications like image processing and CAD/CAM. A multifunction 68901 system console interface chip sets up the units for operation, each of which has its own mini-operating system. This is developed by the system parameters and a console monitor facility software package being stored in the EEprom which also allows for controlling the uploading and downloading of programs and data. The 68SUM operates in a self-contained environment thanks to 32Kb of static RAM, provided as a scratch pad for the EEprom. The board also comes complete with programmable interrupt handling with capabilities extending from 68SUM-to-host to host-to-68SUM. General purpose communications registers are also provided in the 68SUM to identify interrupts. As the Unibus-compatible port in the board is, in practice, a shared memory port, transfers between the host machine and the board can be done without increased traffic load. Up to 256Kb of host memory can be shared via windows, allowing direct access to the 2Mb dynamic memory by the Unibus PDP-11 or VAX as well as direct access to the host’s memory by the 68SUM. The Ranyan model also allows users to download their high level language programs via shared memory, and to receive program results, up to two times faster than running the programs on the host alone. Ranyan’s optional CA68 Cross Assembler enables the 68SUM to be programmed and also means users can develop their own program code in assembly language. Any DEC compatible language compiler can be used in high level programming including Fortran, C, Pascal and Ada. The 68SUM with 2Mb memory has a price tag of UKP3,999 and delivery is currenlty 30 days.
