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ND-505

An ND-500 deliberately narrowed so it could legally be exported to the Eastern bloc.
Introduced ~1982
Type Configuration of ND-500/2
Word length 32-bit
Needs a host? Yes - needs an ND-100
Replaced -
Replaced by -
Survivors Not recorded

The short version

During the Cold War, CoCom - the Coordinating Committee for Multilateral Export Controls - restricted what Western computers could be sold to Eastern bloc countries. A machine above a certain capability could not be exported. The ND-505 is an ND-500/2 cut down to fall below that line, so it could be sold legally.

The mechanism claimed for this is blunt: pin 27 snipped on the backplane, removing its status as a superminicomputer. That specific claim is unverified. What is verified, from ND's own product sheet, is the address width.

Specification

Item Value
CPU ND-500/2 Central Processor
User address space 29 bits - stated in ND's own product sheet [P]
Program space Up to a quarter gigabyte per user
Data space Up to a quarter gigabyte per user. Files can be accessed as if they were arrays
Basic system ND-500/2 CPU, ND-100 front-end processor, controller, system console, 2.25 MB main memory
Instructions Byte-oriented, tailored for FORTRAN DO-loops and COBOL string handling
The pin 27 claim One wiki says a backplane pin was snipped. Unverified - nothing held mentions it [?]
Conflicting figures Norwegian Wikipedia calls it a 28-bit machine; ndwiki says 31-bit physical with 29 for the user. The 29-bit user figure is the documented one

What was new

  • Nothing technically better - this is a machine made deliberately less capable, for political reasons.
  • A rare case of export law shaping a product's specification.

Sources

Full context: MACHINE-TIMELINE.md.