The ND-100 was a 16-bit minicomputer series made by Norsk Data, introduced in 1979. It shipped with the SINTRAN III operating system, and the architecture was based on, and backwards compatible with, the NORD-10 line.
The NORD-100 was originally named the NORD-10/M (M for Micro) as a bitsliced OEM processor. The board was laid out and finished and tested when they realized that the CPU was far faster than the NORD-10/S. The result was that all the marketing material for the new NORD-10/M was discarded, the board was rechristened the NORD-100, and extensively advertised as the successor of the NORD-10 line. Later (the year was 1978), in an effort to internationalize their line, the machine was renamed ND-100.
|Minimum number of microinstructions per instruction||3||3||1||1|
|Minimum microinstruction cycle time||150ns||150ns||100ns||100ns|
The ND-100 line used a custom processor, and like the PDP-11 line, the CPU decided the name of the computer.
- NORD-100/CE, Commercial Extended, with decimal arithmetic instructions
- ND-100/CX, improved the CE instructions and added some new instructions
- ND-110, incrementally improved ND-100. Same performance and instruction set as the ND-100/CX.
- ND-110/CX, a faster version of the ND-110 (1.5-3.5 times faster).
- ND-120/CX, completely redesigned.
- ND-125/CX, a 120 CPU board with faster access to onboard memory and increased onboard memory size.
The ND-100 line was machine-instruction compatible with the Nord-10 line, except for some "extended instructions", all in supervisor mode, mostly used by the operating system. Like most processors of its time, the native bit grouping was octal, despite the 16-bit word length.
The ND-100 was implemented using medium-scale integration (MSI) logic and bit-slice processors.
The ND-100 was frequently sold together with a memory management card, the MMS. The combined power use of these boards was 90 watts. These boards would usually occupy slots 2 and 3, for the CPU and MMS, respectively. Slot 1 was reserved for the Tracer, a hardware debugger system.
The CE stood for Commercial Extended. The processor was upgraded by replacing the microcode PROM.
The ND-110 was an incremental improvement over the ND-100.
The ND-110 combined the Memory Management System and CPU, previously separate cards, on one board. The single CPU/MMS board was plugged into the memory management board slot, usually numbered 3. The power consumption was reduced from 90 watts to 60.
The ND-110 made extensive use of PALs and gate arrays - with "semi-custom" VLSI chips.
The ND-110 had three gate arrays:
- The Micro Instruction Controller, the MIC - also known as RMIC, for "Rask MIC" ("Speedy MIC"). It replaced three 74S482 sequencers and about 30 other ICs.
- The Arithmetical and Logical Unit gate array (ALU, also known as the "BUFALU"). Replaced four Am2901 bit-slice processors, and some additional registers like the data bus register the general purpose register, and the internal register block.
- The Micro Address Controller (The MAC, also called RMAC, for "Rask MAC" ("Speedy MAC"). It implemented hardware address arithmetic, which in the ND-100 had been done in microcode.
In addition to the macro-instruction cache memory also found in the ND-100, the ND-110 had a unique implementation of cache memory on the micro-instruction level. The step known as mapping in the ND-100 was then avoided because the first micro-instruction word of a macro-instruction was written into the control store cache.
Unlike the ND-100 CPU, it handled synchronous interrupts as traps, similar to how it was handled by the ND-500.
The CPU clock and the bus arbitration network were implemented using 15ns PALs.
The main oscillator was a 39.3216 MHz crystal oscillator.
This is the fast version of the ND-110 CPU, also known as RASK.
This is the CPU used in the BUTTERFLY 110 PC-based workstation. The CPU is implemented on two full length ISA cards and based on the same design as ND-110/CX.
The ND-120 CPU was a complete reimplementation on an LSI chip (The so-called Delilah chip), and was originally intended to be sold as the ND-1000, to reflect the technology change, which paralleled the change from the ND-500 series to the ND-5000 (Codenamed Samson).
The Samson/Delilah naming scheme may reflect that around the time of the development of the ND-120, it was increasingly clear that the mixed 16/32-bit architecture was a bottleneck for the ND-500(0) architecture; Internal technical documentation used at Norsk Data for the Delilah chip has a drawing of a grinning woman with hair in her clenched fist.
The ND-125 CPU appears to be based on an ND-120 CPU, but with improved performance by speeding up memory access to the on-board memory, and by increasing the on-board memory size to 8, 12, or 16 megabytes (the ND-120/CX could have a maximum of 6MB on-board). The larger memory size is achieved by using 4-Mbyte SIMMs instead of 1-Mbyte SIPs. Memory cycle time is reduced to 150 ns by using 70 ns memory modules instead of 100 ns modules.
There are quite a lot of surviving ND-100 systems remaining. This list is far from complete.
- ND-100 serial 383 : In the collections of Telemuseet
3002 ND-100 CPU board.