Terminal Data Management Systems

[Endersending]

Computer serial terminals have been a wonder to me and I have been learning about how they work and what you can do with them. Looking through terminal manuals (Televideo 920b) I see these multi 'color'(high intensity, dim, inverse) sales forms and special characters and graphics they use to produce really nice looking interfaces on these old terminals.
After purchasing a televideo 920b and a 950 I have been trying to reproduce these forms using python and printing out the escape codes and everything seems to work in its most crude form.

I am wondering if someone can explain how this was done when terminals where used in businesses or 'back in the day'. How did they build these programs? Reading through a VAX manual they talk about a COBOL library that is used to interface with any terminal you would want to use. Does anyone know of where to find these libraries to program with these types of terminals?
I have been using python curses lately and it works, although even with TERM set correctly most of the features of the terminal don't work (blink, underline, inverse). At this point I have to rake through TERMINFO and find something that works for a 920b better than tvi920b-unk

My end goal is to create input forms for data. an example would be putting a terminal in my garage that I can use to input vehicle maintenance. multiline input fields would be great.
When programming something like this I would like to use the idea of having protected and unprotected fields on the screen and being able to use the keys on the keyboard like 'line erase' 'page erase' 'send page'. The form would be built with fields and the cursor can move to using TAB and then submitting the screen (page) when it is done. This seems to be the way the terminals where designed to be used but I cannot find good information on how this is accomplished. Most tutorials are about games or stuff with colors and features that most real terminals never had and they don't cover the real thing.

any information is always appreciated.
Thanks!

p.s. I am not sure if this is the right place to post this - terminals where used on mainframes so I guess it makes sense.

 

[doshea]

Hopefully you get some more useful responses than this one, but in case you're interested, I watched some of this video recently which explained part of the story for IBM midrange systems:

It's probably easier to find information about those systems since I think they're still doing very similar things now to what they did decades ago - on bitsavers, I saw a manual from 1986 for that Screen Design Aid that appears in the video. Sorry that this isn't useful for implementing your project, I'm just sharing in case you're interested.

I'm actually interested in the answer to your question too, because I'd kind of like to do something like you're doing with my IBM 3476 terminal attached to a Linux PC via one of inmbolmie's converters since getting it to use any display attributes with any regular Linux programs will be a challenge because in termcap terms it effectively has the "magic cookie glitch" (all attributes take up a character location on the screen).

 

[Endersending]

The video was very helpful. It gives me a direction to go. From this I stumbled upon a video about ncurses and guile. Guile seems to be a scripting language like what I am seeking in terms of building these programs. I will keep looking around know that I know some keywords like 'screen design aid'. Maybe someone has some stories about how they would build the code for these terminals

 

[krebizfan]

https://www.microfocus.com/documentation/object-cobol/ocu42/uiscrn.htm is a COBOL screen designer which almost explains how the fields are setup and bound to the database.

If you have used a GUI database front end product, the methods are very similar. I haven't written any COBOL code but I had done some conversions of COBOL programs and was surprised how closely the newer product hewed to the old terminal concepts.