After my PET 2001 I had purchased in 1977/78, I bought a Commodore Vic-20. Using the book, "Practical Astronomy with Your Calculator", I wrote a program in Vic BASIC which was the same as the PET's to identify the four most prominent moons of Jupiter based on their elliptical plane being on edge when viewed from Earth. I wanted a way of going on my roof in Brooklyn with my small refractor to identify them, so I bought a thermal printer and printed out the primitive graphics on a line for a given time for the next few hours or so of stargazing. I can't remember the printer brand, but it wasn't one of the Apple, Atari, or ZX offerings. Good fun. I have to say, I would use my phone nowadays or my e-ink tablet instead. Not from being 'sucked in' but merely because it would be quick and more accurate and have other uses for the same task like Stellarium!