(source: https://www.mikrocontroller.net/attachment/18768/ELV-Platinen.jpg)
ELV is a mail order catalogue. I had this learning kit, released in 1993.
Main board is the large one, kit was 50 DM (built 80 DM incl empty EEPROM and casing). Optional were 3 test circuits (around it, other boards are unrelated). 15-32 DM. An EEPROM with 100 test programs was 30 DM.
Connectors: RS 232 and port connectors.
Very good was the booklet, 80 pages which is a compilation of the parts from the magazine, I think 23 parts. All basics, schematics and even commented listings of the test programs.
They had at least one or two microcontroller kits then, one is PLD ispLSI 1016-80.
Does anybody know more (older) kits from ELV? I bet that there were many MCS-51 kits.