What explains the popularity of terminals with 80×24 and 80×25 displays? A recent blog post “80×25” motivated me to investigate this. The source of 80-column lines is clearly punch cards, as commonly claimed. But why 24 or 25 lines? There are many theories, but I found a simple answer: IBM, in particular its dominance of the terminal market. In 1971, IBM introduced a terminal with an 80×24 display (the 3270) and it soon became the best-selling terminal, forcing competing terminals to match its 80×24 size. The display for the IBM PC added one more line to its screen, making the 80×25 size standard in the PC world. The impact of these systems remains decades later: 80-character lines are still a standard, along with both 80×24 and 80×25 terminal windows.
As noted, a follow-up to our earlier discussion.
It also might be simpler.
Consider even now TVs are more common than monitors.
so there were factories producing the 3:2 ratio (something close to fibonacci) or even parts for them, so you have a landscape TV screen which you can adapt. Since the glyphs for the text characters are higher than wide, how do you optimally pack them onto the screen? And make them clear, readable, visible, distinguishabe, including 0 v.s. O. The 7×5 matrix is the minimum (yes there are attempts but they don’t look right). Even that doesn’t do glyphs below the line.
I remember getting a hi-rez monitor and doing 132×60 or more consoles as a text mode. They are there on the middle graphics cards.
Now I have a 4k monitor, and when I’m not in windows set the font to 8×8 and can see a lot.
Those of us oldies with an electronics background will be very familiar with delay lines. They were ubiquitous in quality analogue oscilloscopes as they allowed the oscilloscope user to see what happened just before the trigger point.
I’ve since upgraded to a 120-wide terminal but in programming many best practises suggest limiting lines in source code to 80 characters at least in one form or another.
80 chars as a hard limit is way too little, but it makes sense for comment lines because then long comments are formatted properly for all people working on that piece of code.