From what I read, most line printers have 132 columns. Also, the VT-220 and presumably other terminals may be switched between 80 columns (that's a usual width) and 132 columns.
As I recall, 80 columns was because of those Fortran punch cards.
But what's special about 132? It's hardly more than 128, which has the advantage of being a power of 2.
As so often with basic measurements like this, the roots have been laid out way before today's computers, even before computers (non human that is) at all.
From what I read, most line printers have 132 columns. Also, the VT-220 and presumably other terminals may be switched between 80 columns (that's a usual width) and 132 columns.
The number is a result of the paper originally used for tabulating machines and a common font size at some later point. In this case it's 14 inch wide paper and a 10 characters per inch printing, which resulted in 132 characters per line - the remaining 8 character positions are omitted for the transport tractor feed pin holes.
But what's special about 132? It's hardly more than 128, which has the advantage of being a power of 2.
As being developed way before the binary computer, powers of two are not related in any way.
It's about the paper.
It begins with tabulating typewriters. Most notably they carry a quite wide carriage able to hold paper of 22 or sometimes more inches wide. Classic (pre-computer *1) ledger sheet size (in the US *2,3) is 22 inches wide (*4). To place tabulating machines into accounting business, similar forms had to be used.
Long story short(*5), the result was support for 10 characters per inch and 6 or 8 lines per inch, and a two paper formats based on a 'half ledger' of 11 inch:
plus a (later) 'condensed' format of
When computers came along, their printers were not only built using the same components as tabulating printers, but more importantly had to adhere to these paper formats to be useful.
Minis (as the mentioned VT terminals) and micros just carried it on - again to make their output useful to the businesses they where meant to be sold to.
*1 - Classic as in genuine handwritten thread-bound ledger books.
*2 - Jup, that's the sheet size where the ledger page size comes from.
*3 - European pre-DIN formats were similar, which opens the interesting notion that the printing press was already setting international standards way before any standardization organization. Just not as systematic.
*4 - Or better most used was 17" x 22". Other common ledger sizes are, 17" x 28", 19" x 24", 24" x 38"
*5 - There was much variation of character density and capability among early machines. For example a IBM 405 only handled 8 character per inch and a total of 88 print bars (positions). At least it could also print letters, where the earlier 285 could only handle numbers.
The United States has its own paper sizes, two of which are 11"x17" ('ledger/tabloid') and 8.5"x11" ('letter'), which are similar to A3 and A4 and have the same sort of predominance.
Early fixed-width font printers usually offered a 12 characters-per-inch typeface.
12*11 = 132; so 132 characters is the number you can fit on a landscape 'letter' page, or a portrait 'ledger' page.
132 column printers were a defacto standard decades before it became common to print on sheet-fed A-size (8.5x11 inch) paper, let alone in sheet-fed in landscape orientation, so an explanation based on 12 CPI and 11-inch long paper in landscape orientation certain is not the origin of the 132-colum standard.
For example, most models of the IBM type 1403 printer, one of the most common high-speed printers in the 1960s and 1970s, had a tractor feed mechanism intended for a paper width 14 7/8 inches, and printed at 10 characters per inch horizontally, spanning 13.2 inches of the paper width, leaving a little less than 7/8 inch margin on both sides, which included the tractor feed holes. There were individual print hammers for each character position, so the character pitch could not be changed, though the number of lines per inch vertically could.
It's possible that the IBM 1403 printer was the main device that popularized 132-column printing on 14 7/8 inch wide paper. Certainly IBM's competitors did their best to copy it. IBM's earlier accounting machines might have used the same paper size, but they didn't print 132 columns. Some of them had a much smaller number of fixed-position columns. The 407 accounting machine, contemporary with the 1403 printer, used 120 columns.
I recently read a truly excellent blog entry more exactly on this subject. Read it here: Accounting machines, the IBM 1403, and why printers standardized on 132 columns.
The summary (from the blog entry) is that the IBM 1403 was an incredibly popular printer that wound up creating a standard that was followed for decades.
Ken Shirrif writes:
After researching this question, I've concluded that there are two answers. The first answer is that there isn't anything special about 132 columns. In particular, early printers used an astoundingly large variety of line widths including 50, 55, 60, 70, 73, 80, 88, 89, 92, 100, 118, 120, 128, 130, 136, 140, 144, 150 and 160 characters.2 This shows there was no strong technical or business reason to use 132 columns. Instead, 132 columns became a de facto standard due to the popularity of the IBM 1401 computer and its high-performance 1403 line printer, which happened to print 132 columns.
The second, more interesting, answer is that a variety of factors in the history of data processing, some dating back a century, led to standardization on several sizes for printed forms. One of these sizes became standard line printer paper holding 132 columns.
The IBM 1403 was a line printer (it printed a line at a time) using a print chain that ran horizontally across the page. It could print 600 lines per minute IBM 1403 at 132 characters/line!
Ken Shirrif also made an animation of how the line printer printed. If you've ever wondered how line printer worked, check out the animation!
For technical reasons it was natural to increase the width of the carriage in multiples of 3 characters. For historical reasons, IBM seemed to like to increase the width in multiples of 12 (from 120 on the previous printer to 132).
Exact paper size wasn't important back then, other than being roughly ledger size. According to the article it was routine to have custom forms printed depending on the task, and paper came in a lot of sizes.
