Sitting in my lab right now, I've got a British sci-fi TV show from September 1967 playing behind me, and I observed one of the characters talking about [quasi] Boolean logic being performed on hexadecimal numbers. At least, he spoke a couple of numbers that would be valid hex bytes :)
When did people start using hex in normal conversations? I associate the late 60s and early 70s more with octal.
First I saw was when IBM introduced the 360 - sometime in the early
1960s.
The funny thing is the radix is misnamed. Decimal in Greek means tenth and Hexa (or Hexi) means Six. The proper Latin term for 16 is Sexa (or Sexi). But IBM, being a bunch of suits could not use a radix where the common name/usage would be shortened to sex.
I used DEC mini's with octal in the early years, and I didn't see hex used until about 1976, but it appears IBM takes the prize one more time. :-)
Don...
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:-) My normal conversations at one point of my life was in either hex or octal. I had a head full of numbers and could rattle off conversions, like kids of the day could do multiplication tables. Don't know if they can do it today with $2 calculators available.
My normal conversation never involved the purchase of eggs. :-)
Don...
--
Don McKenzie
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Crystal clear, super bright OLED LCD (128x128) for your microcontroller.
Simple serial RX/TX interface. Many memory sizes.
http://www.dontronics-shop.com/product.php?productid=16460
As far as I know, sexa- is the latin equivalent to the greek exa-, still related to the number six. Thus, the six-based numeration should be called "exal" or "sexal" (just like "octal" is for eigth-based), even if I've never heard of it.
I suppose that hexadecimal was invented as a composed word (exa- plus deca- equals sixteen). Oddly enough, "sexadecimal" and "hexadecimal" should be synonims, but one is used for base 16 (6+10) and the other for base 60 (6*10).
In the Greek language, "decimal" is translated to "dekadiko" and "hexadecimal" to "dekaexadiko". 10 is translated to "deka" and 16 to "dekaexi". So the proper English equivalent of "hexadecimal" would perhaps be something like "decihexal" (note the order of "deci" and "hex" parts). It is, however, common to put the "deci" part last, hence the word "hexadecimal". Similar cases can be found in the names of polygons in geometry. For example, the regular polygon of 17 sides is called "heptadecagon" in English, whereas the proper Greek word is "dekaeptagono".
Right. Hex doesn't make much sense on 12/18/36-bitters. Octal was also however the standard convention on 16-bit PDP-11 (and, I would aver, for ASCII constants today:).
The 32-bit VAX began to push hex as a standard representation, judging by the 1981 handbook I have at hand, which gives all addresses in hex. Hex's dominance today is connected with the growth of 8/16/32/64 bit architectures, imho.
The first computer I ever wrote programs for was the Monrobot XI, which was built in 1959&60 - perhaps even 1958. It used hexadecimal, but not using A-F for 10-15 - it used RSTUVW. We either didn't have, or I suspect, didn't know how to use, the assembler (the machines had been retired and given to my school, in the 70's), so we wrote machine code and would enter the HEX codes directly through a IBM electric typewriter. These were fitted with mechanical input/output "nets" which did the binary encode/decode for the machines.
They had a 32 bit word, with 2 instructions per word, so you could only jump to an whole word address. I remember some of the opcodes, like "T000" was load from address 000 (12 bit memory address space). Yes that's right folks, people ran major insurance companies on machines that had 4KB of storage! Plus paper tape I/O, and even Monrocard - a magnetic card the size of punchcards.
All memory, including the registers, were stored on a spinning drum which gave an average access latency of 17ms(!), except that the "fast access" registers at addresses 0-6 (6 was the accumulator) had their own drum track and were written 16 times in one revolution, so the write time was still 17ms but the read time closer to 1ms.
They were built by Monroe Corp, of course. Interesting times :-)
The PDP-11 was designed around octal, in the opcode the last three bits selected the register, the next three bits one of eight addressing modes, in two operand instructions the next octal digit selected register and next addressing mode of the other operand, next octal digit selected the dual operand opcode and the MSB was quite frequently used for byte/word selection. Also the MMU extended the address by 6 bits or two octal digits.
The Intel 8080 instruction set is also designed around octal digits with the 8 registers. Apart from some early documents using octal, Intel for some strange reason switched to hexadecimal.
It was quite natural to use hexadecimal, since 16 registers and 16 addressing modes were used. Also consider that you would need 11 octal digits to represent a 32 bit word, while 8 hex digits would be sufficient.
You are probably right; wikipedia redirects from "sexadecimal" to "hexadecimal", it looks like they are synonyms in english. I've also tried with Webster dictionary but this word is in the unabridged (i.e. pay) section.
Anyway I was curious and I've done some google searches, it seems that the italian equivalent of sexadecimal (i.e. "sessadecimale") has actually its own meaning, it isn't just a synonym of hexadecimal; more specifically, the decimal unit of measure of the angles that goes from 0 to 360 - the DEG notation on the calculators - is called "grado sessadecimale":
I use the word "normal" in full awareness of the context where I'm posting, however :) I speak hex almost every day to colleagues, as (I surmise) do most others in this NG.
Interesting. So the word 16 in Italian uses the "6" part first and the "10" last. This is consistent with "hexadecimal" in English. I wonder what the word for "26" is in Italian... Is it also "6" first, "20" last? Because in Greek (and English) it is the other way around.
Having said all that, I like the sound of "hexadecimal". There's a nice ring to it. Maybe because of all those years of using it...
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