The Web Site to Remember National Semiconductor's Series 32000 Family

Multiple Vendors

Many more companies build systems and boards with the Series 32000 chips. In this chapter you find some of them together with some information about their products.


E-LAB was a german company. In 1985 they offered a board called "CPU 32/32" which they claimed to be the first european MultibusII board. The board was based on the NS32032 CPU. Main memory was expandable from 256 kbytes based on 64-kbit memory chips up to 4 Mbytes with 256-kbit memory chips in special sockets and an additional add-on board. The memory could be optionally protected against faults by ECC (Error Correction Code). One bit error could be corrected and two bit errors were detectable. This concept was not found very often in the 1980's. Most vendors prefered parity protection which requires not much hardware ressources.

E-LAB was the only company I know which talked about the NS32132 CPU. They said that the "CPU 32/32" board could be equipped with two NS32132's instead of one NS32032 and the socket for the second CPU is already on the board. Up to now it is still questionable whether this processor had ever existed.

It would be a great miracle if a "CPU 32/32" board still exists. But perhaps somebody had worked with it and can tell some experiences.


Encore was an american company founded around 1983. They sold a system called Multimax. It was one of the first multiprocessor systems based on standard microprocessors. The main idea behind the concept was that a system can be upgraded on customer request. Multimax systems could be configured from 1.5 to 15 MIPS in increments of 1.5 MIPS.

The Multimax system was based on a central high speed bus called Nanobus. This bus had 32 address bits and 64 data bits. It could transfer one word every 80 nanoseconds. The bandwith was 100 Mbytes/second which was a lot in the middle of the 1980's. Four different cards were available : a "Dual Processor Card" (DPC) with two NS32032 CPUs and 32 kbytes cache memory, a "Shared Memory Card" (SMC) with 4 Mbytes of DRAM, a "Ethernet/Mass Storage Card" (EMC) and a "System Control Card" (SCC). The SMC was split into two banks and used ECC. The EMC had an own processer which was also a NS32032 CPU.

A "VMEbus Adapter" (VBA) was also available. The sum of DPCs (up to 10), EMCs (up to 10) and VBA (0 or 1) was limited to 11.

All multiprocessor systems based on the NS32032 CPU had the same problem: the CPU has only 24 address lines. This limits the memory capacity to 16 Mbytes. To overcome this problem engineers from Encore build a special hardware to expand the address bus from 24 bits to 32 bits.

Later Encore introduced the Multimax 520 which used the NS32532 CPU. Up to 20 CPUs could be installed. Again two processors were placed on one board together with 256 kbytes of cache memory. Main memory was now available with a minimum of 32 Mbytes up to a maximum of 640 Mbytes. Encore claimed that one processor delivers 8.5 MIPS at 30 MHz clock frequency and therefore their system has a peak speed of 170 MIPS.

Flexible Computer

Flexible Computer was located in the US. The company build a computer system based on the NS32032 CPU named Flex/32. It was a multiprocessor system which used a maximum of 20 boards. Each board could be a processor board or a memory board. The processor board had one NS32032 CPU and its own DRAM memory with a capacity of 1 to 4 Mbytes. The memory board had 8 Mbytes capacity and was shared between the CPU boards.


Sequent was the third vendor after Encore and Flexible Computer to offer a multiprocessor system based on the NS32032 CPU. Sequent was an american company founded around the same time as Encore. Their system was called Balance 21000. This system offered the biggest number of processors : up to 30 CPUs could be installed. Two NS32032 CPUs together with cache memory were placed on one processor board. The system used only shared memory and was therefore similar to Encore's design.


TRICON builds fault tolerant computer systems. According to a presentation of June 1997 over 2500 TMR (Triplicated Modular Redundant) systems are installed worldwide. On page 24 the main processor architecture is shown. An NS32GX32 CPU together with the NS32381 FPU is used. It would be interesting to see such a system. The presentation can be downloaded here.

Whitechapel Computer Works

Whitechapel Computer Works (WCW) was an english computer manufacturer. Their first product was a NS32016 based workstation. Follow the link to Wikipedia to read more about WCW.

In October 2015 I got an information that an MG-1 workstation without monitor was offered at ebay. The price of the offer was 1,950.00 £ . Although it is quite an interesting machine the price is in my opinion much too high.

This chapter was last modified on 11 June 2017. Next chapter: National Semiconductor