Siemens Field PG. It is a rugged Notebook for PLC programmers. At least in the last version until last year, the "Field PG M6" was possible to buy the Notebook with a special serial port for old S5 PLCs ant the Step5 software came in a special DosBox version with it.

The Field PG has also another special port called "MPI/Profibus" for S7 PLCs, 2 Ethernet ports and a DVD drive.

https://support.industry.siemens.com/cs/document/109766662/d...