
80x25 - paulgerhardt
http://exple.tive.org/blarg/2019/10/23/80x25/
======
PixyMisa
80 characters was the number of characters a 10-pitch typewriter could fit on
a line on standard letter-size paper. 24/25 characters came from the vertical
resolution of CRTs and what you could fit into 2KB of RAM.

The point size argument is clearly wrong, as this sample from the early 19th
century shows:
[https://upload.wikimedia.org/wikipedia/commons/4/45/A_Specim...](https://upload.wikimedia.org/wikipedia/commons/4/45/A_Specimen_by_William_Caslon.jpg)

~~~
zeckalpha
That appears to be typeset, not typewritten.

~~~
gok
But they didn't used typewriters to make punchcards; they used a press.

------
Animats
80, yes. 25 lines, though, had nothing to do with punched cards.

And yes, physical card quality was a big deal. The early feeding mechanisms
relied too much on the card thickness and card edge properties. That lasted
into the 1970s.

Then, near the end of the punched card era, Documation nailed it.[1] They
discovered that if you squirt air into the base of a card stack just right,
you can make the cards separate themselves slightly. Then a vacuum picker can
reliably pick them off one at a time. A neat little piece of machinery, far
simpler than most earlier card readers.

[1]
[https://www.youtube.com/watch?v=qu55b0GpgE8](https://www.youtube.com/watch?v=qu55b0GpgE8)

~~~
saalweachter
The 25 lines comes from the 2 Kb display RAM of the VT52/VT100, plus the
desire for 80-character lines.

~~~
C1sc0cat
the Vt100 had a 132 character mode as well.

They also had shockingly bad protection on the serial port from induced
surges, eventually we brought the full service manual so our in house
electronics shop should could fix ours.

------
bbanyc
I expect the standard would be something like 80x25 regardless, given the size
and resolution of early terminal monitors and how small you could make text
before it's unreadable. Whether a different sized greenback ends up making a
70 or 90 column punched card, it's not that big of a difference from what we
got. The 4:3 aspect ratio is probably the bigger influence.

It's like how rack mounts are 19 inches wide because the Bell System made that
the standard for its telephone relay racks 100 years ago. In the long run it's
more important that there is a standard than what it is.

~~~
flohofwoe
Video memory addressing could have become quite a bit simpler and faster if
the width would be nice round 2^N number (e.g. 32, 64 or 128 characters on a
line), especially on limited 8-bit machines of the 70s and 80s. So 40 or 80 is
indeed a somewhat strange choice (at least those numbers aren't completely odd
though, with 40=(2^5)+(2^3) and 80=(2^6)+(2^4).

~~~
thelazydogsback
TRS-80... 64 chars (or 32 double-width) by 16 lines

------
dperfect
As others have pointed out, the claimed link between banknotes and terminal
dimensions is unclear, if not flat out wrong. The article's own logic is
missing a crucial connection right here:

> At one point sales of punchcards and related tooling constituted a
> completely bonkers 30% of IBM’s annual profit margin, so you can understand
> that IBM had a lot invested in getting that consistently, precisely correct.

> At around this time John Logie Baird invented the first “mechanical
> television”; like punchcards, the first television cameras were hand-cranked
> devices...

It goes on to argue that the television standards influenced terminal
dimensions, but there is no link (unless I missed something) between the
banknote/punchcard discussion and that of the television - other than the fact
that they used hand-cranked devices. No mention as to the punchcard's
size/dimensions being carried over to television (and by extension, terminals)
other than what appears to be a coincidence in the number of characters
fitting on a line of a punchcard.

Looking at the origins of the television standards (at least for the number of
terminal lines, since the number of characters per line seems to have been
influenced by typewriters), one could trace it back to William Kennedy Dickson
(created the 35mm standard by cutting 70mm roll film in half), or previously
to Peter & David Houston and George Eastman for their creation/marketing of
early roll film cameras.

~~~
masswerk
The link is probably as follows: Bank notes -> Hollerith card (80 x 12) ->
Datapoint 2200 terminal (80 x 12, facilitated by 1K Intel linear shift
register for display memory) -> 2K display buffer & 4:3 display dimensions of
silent film (as opposed to the later academy format) as generally used for
television as the major source of demand for readymade raster cathode ray
tubes => two punch cards + 1 extra status line.

The Datapoint 2200, evolving from an original idea about some data editing
device to replace the IBM 029 keypunch, is missing in this account, though.
Announced in 1970 (and shipping in 1971), it predates any of the terminals
mentioned in the article. (BTW, the Datapoint 2200, which was also the
ancestor of the Intel 8008 MPU and by this the ancestor of the modern PC, was
an enormously influential device and is generally underrated for historical
aspects.)

The link between columns on a punch card and typewriters is probably found in
the need for some correspondence between typed tables and information punched
on cards. The aspect ratio of silent film is probably more for esthetic
reasons, since the technical aspect of the width of a frame could have been
addressed by any kind of gearing. However, there's a link between the speed of
the film moving through the camera, the number of exposures per second, the
width of the image, the optical quality of the lens, the shutter construction
and the sensitivity of the film, putting some constrains on the aspect ratio
of choice. (Obviously, if the film is moving too fast and exposure becomes too
short for the chosen material, the resulting image will be dim. The choice of
film sensisitivity, on the other hand, is related to image contrast.)

------
masswerk
Something I missed in this great writeup was the Datapoint 2200 terminal (the
ancestor of the 8008 MPU), announced in 1970 and introduced in 1971. It
originated from an idea about a replacement for the 029 key punch (intended to
replicate the prior success of CTC's Datapoint 3300 terminal as a drop-in
replacement for the ASR 33 TeleType.) From this initial idea the Datapoint
2200 directly inherited the 80 x 12 layout of the Hollerith punch card. (That
this fitted quite perfectly into 1K, certainly didn't hurt and may have been
an incentive for keeping the dimensions of the initial project. Reportedly,
the narrow built height resulting from the narrow 12-lines screen was
generally liked by users.)

Compare: Wood, Lamont. Datapoint: The Lost Story of the Texans Who Invented
the Personal Computer. Hugo House Publishers, 2013.

See also,
[https://en.wikipedia.org/wiki/Datapoint_2200](https://en.wikipedia.org/wiki/Datapoint_2200)

~~~
masswerk
What may be interesting, as well, is that the earlier Datapoint 3300 terminal
(announced in 1967, shipped 1959) already featured a 25 lines display, but at
72 characters per line, just like the ASR 33 it was meant to replace. There
seems to be no hard evidence on how CTC arrived at 25 lines per screen,
though.

Regarding the Datapoint 2260, there's prior art in form of the IBM 2260 Model
3 terminal (1964), featuring 80 characters in 12 rows as well, in direct
correspondence to a punched card. (The Model 1 displayed 40 characters at 6
lines, while the Model 2 managed 40 characters at 12 lines, with only the top
model of the family featuring this relation to punchcards, though. Bonus fact:
the 2260s used a portrait raster tube turned on its side, resulting in
vertical scan lines.)

------
calamityjake
Yup! Python folks don’t seem to think it’s funny when I call the PEP-8
standard, with its 80-column line limit, “punchcard compliant,” though.

~~~
tyingq
I'm one of those that sticks with 80x25 because I had decades of it influence
me.

I do understand, though, that it's dumb, and wouldn't force it on others.

~~~
yoloClin
When I started conforming to it, my code became a lot more concise.

I'd advocate every developer conforms to PEP-8 rules (80-char, nesting limits,
etc), at least for a 3-12 month period. They'll be a better developer for it.

~~~
rlayton2
That's a great idea. Have an opinion about the standard from experience, not
gut feel.

------
yardshop
I remember back in the DOS days being able to type a tiny program into
DEBUG.COM that would set the screen to 80 x 50 mode! It was one of the first
things I would do on a machine if I didn't have my floppy disk of favorite
tools with me. It was just a couple instructions, like MOV AX this and INT 10h
that. Now I have to go find it!

~~~
tenebrisalietum
I thought the MODE command could do this.

~~~
Jaruzel

      MODE CON LINES=50 
    

Indelibly burnt into my long term memory. You needed an EGA or higher graphics
card though.

~~~
lproven
There was also LINES=43 for EGA (640×350, rather than VGA's 640×480).

MODE CO80 was for 80-column colour. ``MODE MONO'' switched to MDA/monochrome
VGA mode (if you hadn't used &b700-b7ff for a UMB.)

MODE CO40 for the 40-column mode intended for the original IBM PC when used
with an analogue TV set as its display.

~~~
Jaruzel
Didn't 'MODE MONO' need a Hercules graphics card though?

------
wil421
Pretty good quote at the end. I’ll have to remember it next time I think I
know something.

>As a personal aside, my two great frustrations with doing any kind of
historical CS research remain the incalculable damage that academic paywalls
have done to the historical record, and the relentless insistence this
industry has on justifying rather than interrogating the status quo. This is
how you end up on Stack Overflow spouting unresearched nonsense about how “4
pixel wide fonts are untidy-looking”. I’ve said this before, and I’ll say it
again: whatever we think about ourselves as programmers and these towering
logic-engines we’ve erected, we’re a lot more superstitious than we realize,
and by telling and retelling these unsourced, inaccurate just-so stories
without ever doing the work of finding the real truth, we’re betraying
ourselves, our history and our future. But it’s pretty goddamned difficult to
convince people that they should actually look things up instead of making up
nonsense when actually looking things up, even for a seemingly simple question
like this one, can cost somebody on the outside edge of an academic paywall
hundreds or thousands of dollars.

~~~
mikestew
The example the author uses reminds me of some wackadoodle numerology BS
proving that the ancient Egyptians predicted the Federal Reserve. "...which
gives us 675, which is close enough to 640, and therefore there had to be a
second shooter". Hey, wait, what? And the comments! "Yeah, that makes sense."
Umm, might I posit that it most certainly does not make a fucking _lick_ of
sense? Yeesh, round off enough numbers, and I've got yer String Theory proof
right here.

------
rootbear
Most early terminals were actually 80x24. I know the DEC VT series were. I
remember being surprised when the IBM PC came out with an 80x25 display.

~~~
kps
_Early_ video terminals had a variety of sizes. The 1964 GE Data Editing
Display (earliest I can find a manual¹ for) had 46×26. The 1967 Datapoint 3300
had 72×25. The 1967 Sanders 720 had (up to) 40×50 or 64×32, depending which
orientation you got the monitor.

But the IBM 2260, their first character display, had 40 or 80 columns by 6 or
12 lines, depending on how much you spent on the controller, which stored a
cluster of terminals' displays on acoustic delay lines.

¹
[https://archive.org/details/bitsavers_geterminalayDec64_1626...](https://archive.org/details/bitsavers_geterminalayDec64_1626712)

------
gok
The leap between IBM punchcards and VT100 makes no sense. Teletypewriters used
72 characters per line. IBM mainframe line printers used 132 characters per
line. DEC and IBM probably just happened to pick 80 character columns for
unrelated reasons (1970s CRT resolution and 1920s printing technology,
respectively)

~~~
Taniwha
It makes lots of sense - as we moved from batch systems to working from
terminals (mid to late 70s) some people were editing cards on card punches,
while others were editing card images on terminals

~~~
gok
So DEC thought of this as a way to edit IBM cards but IBM didn't?

The implicit claim is that somehow the machines for manufacturing punch cards
were reused for computer output and that is what terminals were trying to
emulate. But surely there were more displays and non-card-sized printers?

~~~
Taniwha
Actually I was using Burroughs systems (in pre-VT52 days)

There certainly were non card size printers - but they scaled linearly with
technology

But no we didn't repurpose card punches to be terminals, but we did need
terminals to edit card images (fortran was 72 characters plus 8 digits of
sequence numbers)

------
ncmncm
Apparently the author is not aware that delivering a box of microfiche cards
instead of a fat paper printout was a common practice back then. It had
nothing to do with spooks.

You find that mentioned in Brooks's Mythical Man-month book: everyone working
on OS/360 got a box of microfiche representing the current state of the OS,
each morning. Without a terminal, how else would you look up what a system
call actually did? Printing one copy of all the source, and then optically
reproducing it to more acetate, was obviously more efficient than printing it
hundreds of times.

The old listings would be burnt to recover the silver.

~~~
mikestew
One not need to have even worked on old computer systems. I'm not even retired
yet, and I've gone to the library to look stuff up in old newspapers that were
on microfiche. When I was a mechanic back in the day, parts listings were on
"fish", too.

I think the author read "microfilm" and instead of hearing a synonym for the
thing car parts are listed on, I'd bet the immediate thought was little micro
spy cameras to put your microfilm in.

------
cryptonector
Where TFA goes from talking about punch cards to 35mm film with audio track to
4:3 film and CRT aspect ratios, there's a disconnect: there's nothing to tie
film/TV aspect ratios to punch cards. TFA then tries to construct a tie from:

> Fascinatingly, the early versions of the ECMA-48 standard specify that this
> standard isn’t solely meant for displays, specifying that “examples of
> devices conforming to this concept are: an alpha-numeric display device, a
> printer or a microfilm output device.”

TFA should know that terminals evolved to be a keyboard + printer before they
evolved to be a keyboard + CRT. I'm not sure that there's any link between
paper size and CRT size. Most likely the only connection would be number of
columns (of fixed-width text), but not lines.

My guess is that in the end there's no connection between punch cards and
terminals being 80x25, much less between Civil War Demand Notes and terminals
being 80x25. 80x25 was just convenient for all the independent reasons TFA
lists. Any similarity to punch cards was almost certainly coincidental, and
perhaps convenient.

~~~
Doxin
> I'm not sure that there's any link between paper size and CRT size. Most
> likely the only connection would be number of columns (of fixed-width text),
> but not lines

I haven't got a solid answer here, but I do know from experience that your
average typewriter does about 80 characters across a page once you account for
margins.

Now clearly that'd not be much of an argument if margins are arbitrary but I
don't think they are. On a typewriter your can more or less freely choose the
top, left, and right margin. The bottom margin is however limited by the
mechanism: by the time the bottom of the page is under the striking area the
paper is flopping in the breeze since the roller isn't holding it anymore. If
you set the left and the right margins (and the top margin) to the same size
as the minimum workable bottom margin you end up with roughly 80 characters
across the page.

Seems as likely a link as any: typing out tabular data from a punch card would
be limited to the same width as common on typewriters.

~~~
cryptonector
Sure, but all these links (like the 2KB link) seem a bit coincidental. Of
course, 2KB would fit other combinations of columns and lines, and typewrites
(I think? I don't have one at hand!) probably do manage to fit more than 25
lines of single-spaced text with normal margins... My _guess_ is that matching
typewriter (and/or punchcard) width was more important than matching length,
so with 1KB and 2KB, terminal manufacturers used as many lines as they could
fit while using 80 column lines. Display width is probably more important than
display length for us humans.

------
manicdee
Is this another variant of space shuttle SRBs being the width of two horses
arses?

------
WalterBright
I designed and built an ASCII terminal as a college project. The 25 lines was
set by the number of lines a standard monitor could display, given a certain
number of scan lines needed to make the font legible.

As monitors that could display more scan lines became available, people
instantly used them to display more rows.

------
thangalin
A related post about software development, history, surveillance, knowledge,
weaving looms, terminal sizes, and more:

[https://dave.autonoma.ca/blog/2019/06/06/web-of-
knowledge/](https://dave.autonoma.ca/blog/2019/06/06/web-of-knowledge/)

------
Mountain_Skies
Hugged already? Archive:
[https://web.archive.org/web/20191024002534/http://exple.tive...](https://web.archive.org/web/20191024002534/http://exple.tive.org/blarg/2019/10/23/80x25/)

------
sevensor
While I greatly enjoyed the article and its effort at historical synthesis,
the author cites a fact that's not _exactly_ true:

> Then in 1983 the Apple IIe was introduced, the first Apple computer to
> natively support an 80×24 text display, doubling the 40×24 default of their
> earlier hardware.

My family had an Apple IIe in 1984. It only showed 40 columns until my fater
went out and bought an "80 column card" to upgrade it. He also sprang for a
second floppy drive. So "natively" is a bit of a stretch there.

------
yodon
I can't get the page to open but the title of the HN submission is nonsense.

Terminal is 80x25 because that's how big terminals were back in the day (for
very long ago values of back in the day and for purely bandwidth driven
reasons).

Pre-Mac (technically pre-Lisa) Black and White CRT displays which were made
using then-current CRT TV technology which had just enough analog bandwidth to
show 80 columns of 5 pixel by 7 pixel characters, with one pixel separation
(480 pixels horizontally [edit added: those are US numbers, European TV's had
slightly higher bandwidth but that's a different topic]) and most could only
show 24 such characters vertically due to the 4x3 aspect ratio used in
essentially all CRTs of the day. 24x80 was the industry standard for a screen
of text for purely CRT bandwidth reasons. So why 25 lines? Because a few super
cool terminals allowed you one extra line for showing status below a
conventional 24x80 layout, hence 25x80 (vertical squeeze didn't pose bandwidth
or pixel separation problems on black and white displays of that era).
Terminal naturally went with the cool kid size of 25x80. No civil war bank
notes involved, just the bandwidth of then-current generation TV display
technology and a fortuitous coincidence that punch cards had 80 columns.

[edit added] Apple][ and other similar era devices had even lower character
counts because they hooked up to color TV's which had roughly similar
bandwidth but needed to spread that bandwidth across three phosphors per pixel
so far fewer pixels available on screen.

~~~
IIAOPSW
Your being downvoted but you have a valid point. People should look up the
NTSC/PAL standard for how analog TV screens worked. There were only ~560 scan
lines in the raster pattern (vertical and horizontal blanking intervals
notwithstanding). With a character height of 7 pixels/scan lines + one for
spacing that gets you 70 lines of text on screen. Even if the punch card
machines gave you more memory, actually using it would have required buying a
special purpose TV. Eventually we did get CRT monitors which were specific for
computers instead of television, but that wouldn't be economically viable at
the time.

~~~
tyingq
The downvoting is likely because 80x24/25 happened well before home PCs that
displayed via NTSC/PAL. And many of those early terminals also supported a 132
column mode.

~~~
IIAOPSW
What were the earlier non-home computers displaying on?

~~~
tyingq
CRT, but not via RF modulators, NTSC, PAL, etc.

~~~
IIAOPSW
That's very odd. Why did they invent a new CRT format and spend the cost of
the hardware to implement it instead of using an off the shelf TV?

~~~
tyingq
Because TVs didn't have high quality video inputs. Old Apples, C64s, etc, came
with a "tiny tv broadcaster" (RF modulator) that broadcast the signal on
channel 3. In shit NTSC or PAL quality, which is lower resolution than what
the CRT can display.

~~~
IIAOPSW
I understood that. I'm old enough to remember VCR's / game consoles required
you to turn to channel 3 or 4. But what were the older, non-personal terminals
using? Was there some sort of RF modulated raster pattern optimized for
displaying text? Were they drawing everything as vectors? Did they use off the
shelf CRT's?

~~~
tyingq
Direct manipulation of the beam with analog voltage to a CRT driver for the x
and y axis. Same as what the TV does inside.

------
evacchi
from the same author, why arrays are zero-based
[http://exple.tive.org/blarg/2013/10/22/citation-
needed/](http://exple.tive.org/blarg/2013/10/22/citation-needed/)

------
droithomme
This article is complete nonsense.

------
fortran77
I thought this aside about how Wikipedia has been taken over by extremists was
even more interesting:

> _It’s difficult to research anything about the early days of American
> currency on Wikipedia these days; that space has been thoroughly colonized
> by the goldbug /sovcit cranks. You wouldn’t notice it from a casual
> examination, which is of course the plan; that festering rathole is tucked
> away down in the references, where articles will fold a seemingly innocuous
> line somewhere into the middle, tagged with an exceptionally dodgy
> reference. You’ll learn that “the shift from demand notes to treasury notes
> meant they could no longer be redeemed for gold coins[1]” – which is
> strictly true! – but if you chase down that footnote you wind up somewhere
> with a name like “Lincoln’s Treason – Fiat Currency, Maritime Law And The
> U.S. Treasury’s Conspiracy To Enslave America”, which I promise I am only
> barely exaggerating about._

~~~
biggestdecision
For obscure conspiracy topics, the only people who care enough to edit the
pages are the true believers. Today arguments about which occult order is
descended from which happen on Wikipedia talk pages.

Look at this nonsense:

[https://en.wikipedia.org/wiki/Talk:A%E2%88%B4A%E2%88%B4](https://en.wikipedia.org/wiki/Talk:A%E2%88%B4A%E2%88%B4)

> _I am an initiate of the A. '.A.'. and the Golden Dawn. If anyone would like
> to challenge the factual basis of my claim that the System of the A.'.A.'.
> is based on the Merkabah Seven Palaces rather than the Kabbalistic Tree of
> Life, then please provide your reasons for doing so before demanding book
> citations be produced for initiated and previously secret knowledge. Prove
> the A.'.A.'. is based on the Tree of Life or be Silent._

[https://en.wikipedia.org/wiki/Talk:Hermetic_Order_of_the_Gol...](https://en.wikipedia.org/wiki/Talk:Hermetic_Order_of_the_Golden_Dawn/Archive_5)

> _The registered trademark should remain on the Hermetic Order of the Golden
> Dawn, the outer order of the Rosicrucian Order of Alpha et Omega entry in
> the contemporary orders section, as they own the HOGD trademark in Europe
> and Canada. Recently the HOG /A+O settled litigation victoriously preserving
> their perpetual and irrevocable right to use the name of their outer order,
> the Hermetic Order of the Golden Dawn, without interference in the USA. The
> registered trademark rightly and properly distinguishes the HOG/A+O from the
> exorbitant number of -unlicensed Golden Dawn based study groups and should
> NOT be removed. The registered trademark is a distinguishing character
> integral to the association of, and a privilege entitled by law reserved
> exclusively for the HOGD/A+O as the owners of the Hermetic Order of the
> Golden Dawn in the European Union and Canada as aforementioned. It is
> certainly improper and somewhat unlawful to deprive the HOGD/A+O of using
> that privilege of the registered trademark they reserve the right to fully
> represent themselves therewith. Please do not remove the trademarks from the
> HOGD/A+O entry again._

> _Furthermore, as the A+O’s outer order is named the Hermetic Order of the
> Golden Dawn and they reserve all rights to that mark in the European Union
> and Canada. It should be correctly stated in the contemporary orders section
> that the HOGD /A+O is: “a modern order headquartered in the European Union
> using the same name being also the outer order of the Rosicrucian Order of
> Alpha et Omega®. This is paramount, as it distinguishes the HOGD/A+O as a
> completely separate entity from the independent organisation which is the
> HOGD, Inc. who are a modern independent order of the same name._

~~~
chrisshroba
"The amount of energy necessary to refute bullshit is an order of magnitude
bigger than to produce it." \- Alberto Brandolini

------
xellisx
I couldn't finish reading it, but something about a printing press,
typewriters, paper size and the max characters that can fit with a 20 pt font.

------
thrower123
> It’s not entirely clear if this is a deliberate exercise in coordinated
> crank-wank or just years of accumulated flotsam from the usual debate-club
> dead-enders hanging off the starboard side of the Overton window. There’s
> plenty of idiots out there that aren’t quite useful enough to work the
> k-cups at the Heritage Institute, and I guess they’re doing something with
> their time, but the whole thing has a certain sinister elegance to it that
> the Randroid crowd can’t usually muster. I’ve got my doubts either way, and
> I honestly don’t care to dive deep enough into that sewer to settle them.
> Either way, it’s always good to be reminded that the goldbug/randroid/sovcit
> crank spectrum shares a common ideological klancestor.

Is this the kind of tinfoil hattery that is acceptable now?

~~~
ncmncm
It is off topic, but worth mention.

