From the markings on the chips inside we conclude it is manufactured around 1986.
The first power-up was not very successful. Just after a few seconds there were a big smoke cloud coming out right at the power inlet. When investigating this further it was recognized that the EMI-filter on the inlet had their capacitors to pass away leaving a fair amount of tar inside the unit. Luckily, still after 30 years it is possible to purchase exactly the same input filter so after a few days we could power up this for real.
This was now it was recognized that this terminal was not at all like the one described in the manual. Instead this was an IBM terminal of some sort. Hence the name of the firmware, 374/SNA.
Google helped us to understand more by giving this old 1989 ad form the Informer 213.
According to the add is is a an IBM 3178 compatible terminal emulating the 3274 control unit. Exactly what this is about remains to be investigated. However it seems to be quite clear that unless we are able to find a new firmware (which hopefully is the only thing that is needed) we have very little use for this since we have no compatible IBM equipment.
The logic module itself had a 68B09 CPU, 64 kbyte of DRAM, a 27256 EPROM and some static RAM (presumably battery backed by a 3V Lithium cell). Then there was a NEC manufactured ASIC marked Informer, which seems to be the CRTC controller. Close to the other end is two more SRAMs and a 2764 EPROM which probably is the character generator ROM.
There is also a Zilog SCC to do all sorts of serial communication.
The display unit is a electro luminescent display made by Finnish Lohja Corp / (Finlux brand). It has 512 x 256 pixels resolution. To the right is a the drive electronics for the display unit.
Does anyone have more information on the Informer 213 AE? How does it attaches to an IBM system? Does anyone have firmware images that would make this a VT100 terminal?
If this is not the case I put this little thing up for trade for something interesting.