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


In May 2018 I learned that the german company AEG had built a measurement board based on a Series 32000 processor. The board in Figure 1 was obviously an analog control board and was used in a big system in the pharma industry according to the previous owner. The name of the board could be MCU032. This is printed on the backside.

The board uses the NS32CG16 embedded CPU. Additional processing power comes from the FPU NS32081. The available memory is 320 kBytes of SRAM and 256 kBytes of EPROM. This is a lot and leds to the assumption that the board is able to work on itself. Maybe only simple messages were given to a higher level control computer.

Fig. 1. The top side of the AEG board shows a clear separation between the analog (left) and digital (right) functions.

The format of the board is double Euro card. The address latches are placed below the memory chips. This is a space saving design and is found on other boards as well. In the lower right area five PALs of the type 22V10 can be seen. Together they represent many logic gates and flipflops.

The labels on the EPROMs are dated from February 1991. The EPROMs were programmed more than once due to the rest of older labels on them.

Main parts of the analog section are two 12 bit DACs from Analog Devices (AD667JN) and two 12 bit ADCs from an unknown company. The name HADC574 should mean the industry standard type ADC574.

Fig. 2. The solder side of the AEG board. The notes on the front panel were made by the previous owner.

The previous owner made a test with a terminal to one of the DB9 connectors. The test was successful and he saw some text. This was a good info and I will repeat the test in the future.

It is always interesting to read the content of an EPROM if one is not able to operate the system. In this case I found the names of two programmers, see Figures 3 and 4 below.

Fig. 3. Part of the EPROM content showing the name H. Lambrecht and what he (or she) had done for the system.

Fig. 4. A similar info for another part of the EPROM content naming M. Hampf as the programmer.

The date of the programs is 1986. At this time the NS32CG16 did not exist. Obviously there must exist a predecessor of the board based on some earlier processor of the NS32000 family. A search with the words "LOGIDYN" and "AEG" resulted in a company named AEG Industrial Engineering. They still provide a service for old industrial control systems from AEG. But they couldn't help me.

With no documentation about the hardware it will be difficult to operate the complete board. For example the DACs and ADCs need other voltages than 5 volt. But it is not impossible to reverse engineer the schematic of the board. A nice job for the retirement...

Fig.5. Another MCU032 offered by the Company Radwell. They gave me the permission to present the photo.

Radwell sells replacement parts for industrial equipment. Obviously the MCU032 is still in use.

The board shown in Figure 5 is different from my one. First inside the socket for the NS32202 ICU is an IC in a ceramic package. It could be the original ICU from the 80's. But the lid is too big. The second difference is an add-on board placed in the socket for the NS32081 FPU. The chip on the board should be the faster FPU NS32181.

This chapter was last modified on 9 February 2020. Next chapter: AIS