ND-5000 family

The ND-5000 family is the third generations system based on the ND-500 architecture. It is a totally new construction both in hardware and physical layout. The ND-5000 CPU uses the same instructions as the ND-500 CPU but adds 25 new instructions called '87 extensions', also found in the ND-500/1 and ND-500/2 CPUs.

The new ND-5000 CPU replaces 24 cards in the old ND-500 arcitecture. The single processor ND-5700 system have the same computational power as a ND-570 system.

The ND-5000 series of computers is able to run both SINTRAN III and NDIX, Norsk Data's version of UNIX.

Hardware implementation
The ND-5000 family systems uses a ND-100/ND-110/ND-120 CPU as I/O processor.

CPU types
The ND-5000 CPUs came in 3 types. Type 1 had two layers of cards, type 2 had three layers of cards, and type 3 had four layers of cards. Type 1 and type 2 used similar mother boards/baby modules, the difference was that a layer with instruction/data cache and the AAP (Additional Arithmetic Processor) was missing in the type 1 CPUs. The missing AAP meant that on type 1 CPUs floating point operations were performed by the microprogram.

System performance
The difference in performance between models was mainly done by 3 methods: Different combinations of the above resulted in the different ND-5000 models. The table below illustrates this.
 * Select a CPU (Type 1 / Type 2 / Type 3).
 * Jumper the master clock speed to Slow (156 ns) or Normal (70 ns).
 * Disable or enable a number or performance enhancing caching features.

Models
The original series of ND-5000 computers came in three different models, ND-5700, ND-5800 and ND-5900. The ND-5900 models are the same as the ND-5800, but with multiple CPUs (2, 3 or 4). Later additions to the family were Compact models, ND-5200 Compact and ND-5700 Compact.

Reference

 * NEWS March 1987, pg. 52-53, "The ND-5000 Series: Removing Hardware Limitations".