NORD-50

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The NORD-50 computer system is a completely integrated system of NORD-10/S and NORD-50 CPUs. The I/O system, file system and operating system are common to both processors.

The NORD-50 CPU was used in the ND 1100/S, ND 1200/S, ND 1300/S and ND 1400/S systems.<ND>

The NORD-50 CPU is designed to be a fast floating point processor which is a total slave to the NORD-10/S.

NORD-50 does not have an I/O system or interrupt system by itself, all I/O is done through the NORD-10/S which submits jobs to NORD-50 for execution in batches. The NORD-10 acts as a system supervisor running the operating system SINTRAN III/VS and the NORD-50 monitor.

In a NORD-50 computer system, the NORD-10/S has the following functions:

• Supervision and synchronization of the NORD-50s in the system.
• Running the operating system, SINTRAN III.
• Generating NORD-50 executable machine code via NORD-50 assembler or FORTRAN compiler.
• Being the I/O system for the NORD-50s performing I/O transfer to / from the NORD-50 memory.

The NORD-50s in the system perform execution of instructions with data supplied through the NORD-10/S I/O system from byte oriented devices such as terminals, general DMA devices such as disks and magnetic tapes, the universal DMA interface, and special high-speed DMA channels connected directly to ports in the multiport memory system.

The system architecture is such that NORD-50s can have their private memories including a high speed static memory in addition to the multiport memory system.

The NORD-50s themselves do not perform any tasks except for running the application programs.

The slave processor NORD-50 is activated by the NORD-10/S and NORD-50 executes programs in parallel with the activities in NORD-10/S. The NORD-10/S is interrupted when the NORD-50 comes to an end of its tasks.

To the NORD-10 the NORD-50 looks like any else device and is controlled via standard IOX instructions.

CPU

The NORD-50 CPU has a word length of 32 bits.

There are a number of registers in the NORD-50 CPU.

• 64 general data registers with register 0 always containing zero.
• The 64 general registers can be combined in pairs as 32 64 bit floating point registers.
• The lower 16 registers can be used as base or index registers for addressing.
• There are 65 instructions in the NORD-50 CPU.

Address space

The NORD-50 has a 4 megabytes physical address space but the maximum memory it can be equipped with was 1 Mbyte (1976).

Circuit Boards

(Main article : NORD-50 boards)

Main registers and arithmetic, communication registers NORD-10/NORD-50, memory address and data lines, line drivers for external arithmetic are organized on three different boards, each handling four bits:

• 1501 Address Arithmetic
• 1502 Register
• 1503 Arithmetic Buffer

The 32 bit CPU uses eight of each board, making a total of 24 boards located in the middle crate. The top crate contains hardware for multiplication and division, while the bottom crate contains arithmetic circuitry and NORD-10 bus connectors.

The timing and control section of the CPU uses eight different boards:

• 1500 NORD-50 I/O Control
• 1504 NORD-50 Controller
• 1505 Register Address
• 1506 Cycle Counter
• 1507 Arithmetic Control
• 1508 Chip Select
• 1510 Instruction Control
• 1519 Timing Control

Operators panel

The operators panel on the NORD-50 is simpler than the panel on the NORD-10. It is more of a status display than a operators panel. It contains :

• Power lock switch (with a key) and a start switch
• 16 lamps showing bit 0-15 of the active address block.
• Parity check, showing parity errors
  • 4 status lamps
    • Parity error
    • Instruction read
    • Indirect reference
    • Data reference
  • 4 byte lamps showing which byte triggered the parity error
• 2 control switches
  • Display PC
  • Display dataref
• 8 status lamps
  • Memory examine
  • Memory deposit
  • Simulate instruction
  • Simulate data
  • Status break
  • External stop
  • Stop
  • Run

The operators panel is connected directly to the NORD-50 I/O CONTROL board 1500 in position B32.

Performance

Whetstone results

MWIPS	MWIPS double precision	Language	Date
0.531	0.451	Fortran	1975

Remaining machines

This is a first shot at a list of remaining machines. Also machines that is known to be lost will be listed to make it easier to locate remaining ones. We don't have any production numbers yet.

• NORD-50 with unknown serial is in the collection of Trøim, in Telemuseums storage in Fetsund (2016 inventory).
• NORD-50 with unknown serial is part of the collection of Datormuseum.se

Lost machines

• NORD-50 snr 11 was bought by Boliden in Sweden. Later donated to Forskarföreningen Umeå Naturvetare, also known as FUN. The machine were scrapped short before the society was disbanded. Only a few manuals remains.

Related

NORD-50 (command)

NORD-50 monitor