All-in-One (AiO) Trainers:
A few weeks ago, such a configuration seemed to be well within the realms of feasibility. Now it is up and running . . .
The digital analog computer with an auxiliary troubleshooting unit on top (will be mounted only during bring-up and for troubleshooting tough dogs) . . .
Making good use of inexpensive small tablets...
Sometimes, the simplest will be the best: toggle switches to provide a test stimulus and LEDs or the like to observe the response:
Emulation of legacy interfaces
Display modules in comparison:
... vs. LCD
The basics of XY presentation: