Yes Ken that's a little worrying, When I first started in automation most PLC code was either on a handheld or a purpose unit like the SQD console or the OMRON console, most of these had tape drives & if you were lucky a floppy.
Carting these things about stretched your arms so you looked like an Ape.
The first "PC" we had was a Zenith laptop monocrome with twin floppies I think it cost about £2,500, then we upgraded to the same make but with a 10mb hard drive, we were still using the consoles but these over time were upgraded as required like the Siemens PG's the 675 (twin floppy), the 685 with a 10mb HD & then the others like OS2 based with DRDOS & CPM. eventually, to the Siemens field pg's which were windows based, however, the S5 IDE was still CPM based but they used a CPM simulator to run S5 in dos.