> $ is so important in business that every typewriter has one
I actually had a typewriter without one. I would simulate it with S <backspace> / which was not very satisfactory but generally understandable in context.
Was it a US typewriter? This peso symbol is very important in business in the US and Latin America but not, for example, England, Ireland, India, Finland, or Sweden.
It would depend on the age of the typewriter, even the US. Many early ones did not have dedicated keys for symbols, which were made as the parent describes: by going back and typing another character over them (e.g., S backspace / to get a dollar sign).
Sure, I used one back in the 01980s where "!" was "'." with a backspace in between to overstrike them. And of course that's also what _, ^, `, etc., are for.
It was, a Smith-Corona, but it was a scientific version where the characters that were normally on the "shifted" top row number keys were instead subscripted numbers. So you could type chemical formulas with proper subscripts (or roll the paper down one notch and have superscripts) but it wasn't great for normal writing.
I know this symbol is used for pesos, but when 24 countries refer to it as "dollar"[0] compared to 7 for "peso" it seems fair to call it a dollar symbol? Not to mention that it's referred to as "dollar" in unicode.
It's also very interesting to me that [1] mentions it can have one or two bars but in the list above the double-barred version is not only not in unicode but refers specifically to the cifrão[2].
I guess the TLDR is currency stuff is confusing and nonstandard more often than not.
It's a peso sign. The English word for the Spanish "peso" at the time was "dollar", and the US dollar was initially defined to be equal to the Spanish "dollar". The US dollar, which was a coin, had the same value as the Spanish peso because it consisted of the same weight (in Spanish, "peso") of silver. So the US used the peso sign for its dollars. Unicode calls it a "dollar sign" because that's what ASCII calls it, and that's because ASCII is from the US. But it's really a peso sign.
> In most countries of the Americas, the symbol commonly known as dollar sign, "$", was originally used as an abbreviation of "pesos" and later adopted by the dollar. The dollar itself actually originated from the peso or Spanish dollar in the late 18th century.
> The symbol appears in business correspondence in the 1770s from Spanish America, the early independent U.S., British America and Britain, referring to the Spanish American peso,[1][2] also known as "Spanish dollar" or "piece of eight" in British America. Those coins provided the model for the currency that the United States adopted in 1792, and for the larger coins of the new Spanish American republics, such as the Mexican peso, Argentine peso, Peruvian real, and Bolivian sol coins.
> Most theories trace the origin of the "$" symbol, which originally had two vertical bars, to the pillars of Hercules wrapped in ribbons that appear on the reverse side of the Spanish dollar.[6] ¶ The term peso was used in Spanish to refer to this denomination, (...)
c. 1200, pece, "fixed amount, measure, portion;" c. 1300, "fragment of an object, bit of a whole, slice of meat; separate fragment, section, or part," from Old French piece "piece, bit portion; item; coin" (12c.), from Vulgar Latin pettia, probably from Gaulish pettsi (compare Welsh peth "thing," Breton pez "piece, a little"), perhaps from an Old Celtic base kwezd-i-, from PIE root kwezd- "a part, piece" (source also of Russian chast' "part").
So yes, it looks like coincidence.
(Peso is a word in Spanish and up until modern times, there's very little transfer from English to Spanish)
The phonetics would have been even more similar at the time, but I suspect it's a coincidence. The words stem from different origins†, the sense development of "piece" is straightforward (a coin was a chunk of precious metal cut off the end of an ingot, thus being a piece of that ingot, and struck), and the chronology is probably wrong for a phonetic influence. https://www.etymonline.com/word/piece says "piece" for a coin is "c. 1400", which would be about 200 years older than the earliest attested occurrence of "piece of eight" and 100 years older than the peso itself, which was introduced in 01497.
However, the earliest attestation given in https://archive.org/details/oed07arch/page/836/mode/1up?view... is from 01575, in Scots: "To be payit all in half mark pecis," and the first attestation of "piece of eight" is from 01610: "Round trunkes, Furnish'd with pistolets, and pieces of eight." Maybe Etymonline knows of a much earlier attestation? Because if "piece" in the sense of "coin" really didn't come into use until the late 16th century, a phonetic influence would be much more plausible.
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† "Peso", like "poise", is from Latin "pensum", "weight", which may be from "pensare", the frequentative of "pendere", "to hang, to weigh", while "piece" comes from Latin "petia" or "pecia", "fragment". In Spanish today "peso" is still the normal word for "weight" (and "pesar" is the normal verb for "weigh") and "pieza" is still a fairly common word for "fragment".
The double-barred version is not in Unicode because it's just font variations for the same abstract character. Just like the letter g can be written with one or two loops (just look at Helvetica vs Times); Unicode treats it as a font difference. This is called an allograph. Using Baskerville in iOS to render the $ character shows two bars (there are many different variations of Baskerville though).