I found some more older PLC programming devices.
Very interesting keyboard on this Fanal Fanalog PU1262. And CRT display.
Octal in 2 rows. STOP, JA NEIN (Yes, no) and I think 4 arrows.
Fanalog 1251 is completely different
iF Design - FANALOG-Programmiergerät PU 1251
I found some old companies here.
Steuerungen / Hersteller aus vergangenen Zeiten =) | SPS-Forum - Automatisierung und Elektrotechnik
Another interesting one (not sure if octal) but programming via ladder diagram is the Telemecanique TSX T407. QWERTY keyboard and LCD display.
Interesting is also the Openplc Project to be used on Windows, Linux, Arduino, Raspberry Pi and some others.
The graphical programming languages (ladder diagram (German KOP) and function block (FUP, FBS)) will be converted. Some hardware seem cheap, but for a full system or a trainer it’s very expensive and only useful if someone really wants to use it.
There is also a PLC for the Z80 NDR computer. Even when not having that hardware, the software, descriptions and manuals are interesting (in German but with examples and comparison of ladder diagram and instructions.
But both are not in octal.
The Fanal Fanalog PU1262 (what a name!) is a nice looking machine.
The various letter keys seem to hint at a special purpose machine language input, probably (once again) implemented in microcode? There seems to be a pattern with these devices…
I found an interesting OMRON programming device like PR013. Not octal but with keys to enter directly ladder logic (in German KOP, Kontaktplan). There’s also a FUN key.
OMRON is compatible with the German FESTO PLCs. Not sure if these are official rebuilts.
Eg. Festo FPC 201 = Omron C20.
I also have tested some simulation software including ladder logic software for DOS.
Some can also convert to other PLC input styles and to the standard Siemens (S5/S7) format.
Most software I found have issues or demo limitations, like a time or size limit. At least there are often demo files.
I also found a good tutorial PDF showing different ways of programming traffic lights.
All early PLC manufacturers had their own programming. But most supported ladder logic directly or indirectly. But as there are different purposes like FESTO was mainly for pneumatics, there are different parts, symbols and functions. So some conversions are difficult.