Back when I was in high school, in the early 1980s, was when I was first introduced to computer games. What we called "arcade games" at the time.
There were three common systems for this.
First of all, there was the TRS-80. You can read about all the exciting detail in the link, but the system could display text at 64 x 18, and graphics at a resolution of 128 x 48 if you used the special 2x3 grid characters. Each pixel was either black or an interesting blue/white (the phosphor used in the monitor was not pure white).
In addition to not having any storage built in, it also had no sound output whatsoever. However, it was well-renowned for putting out tremendous amounts of RF interference, and somebody discovered that if you put an AM radio next to it, you could, through use of timing loops, generate interference that was somewhat related to what was going on in the game.
But it was cheap. Not cheap enough for me to afford one, but cheap.
The second system was the Apple II, sporting 280x192 high-resolution color graphics. Well, 'kindof-color' graphics - any pixel could be white or black, but only odd ones could be green or orange, and only even ones could be violet or blue.
The sound system was a great improvement over the TRS-80, with a speaker that you could toggle to off or on. Not off or on with a tone, just off or on - any tone had to be done in software synthesis.
Finally, the third system was the Atari 800 and 400. It was far more sophisticated - not only did it have the 6502 as the Apple II did, it had a separate graphics processor (named Antic) that worked its way through a display list, a television interface processor that implemented player-missile graphics (aka "sprites") and collision detection in hardware, and a third custom chip that handles the keyboard, 4-channel sound output, and controllers (we called them "paddles" and "joysticks" back then).
It was light-years beyond the Apple in sophistication, which only shows you the importance of cheapness over elegance of design and implementation.
Oh, and you could plug *cartridges* into it, so you didn't have to wait for your game to load from the cassette (or later, floppy disk) before you played it.
My brother-in-law bought an Atari 400 (the younger sibling of the 800), and of course he had a copy of Star Raiders, arguably one of the first good first-person shooters. He also had a copy of Miner 2049er, a 2-D walker/jumper that's a little bit like donkey kong and a bit like pac man.
It was very addictive, and put 10 levels into a small cartridge.
It was followed in 1984 by "Bounty Bob Strikes Back", featuring 30 levels.
I played both a fair bit until we finally broke down and sold our Atari 800XL in the early 1990s.
And now, Big Five software has released both games in emulator form, so you can run them on your PC.
Marvel to the advanced graphics, and wonderful sound. Note that the gameplay and addiction is still there.
I have to run it at 640x480 size or the keys aren't sensed correctly. Play Miner first, as the controls are slightly different, and you'll get confused.