8.3 Naming Convention: Why was it chosen?

Hiya! Was just wondering if any of you had an answer to this, as my teacher is giving out 1% to my final mark if I can get the answer he wants. So far these are what I've gave him:


This is the e-mail I sent the teacher:

> Is it....
>
> 1) Memory was costly at the time so they used shorter names?
>
> 2) They took it from CP/M in order to make file transfers between CP/M and
> DOS easier to manage?
>
> 3) There are 32 bytes containing things such as: File, address, length,
> time, date stamps, while 11 are set aside for the 8.3?


And this is what i got back:

All you mentioned in your e-mail was correct, except you didn't tell my why 8.3
was "chosen."


Any more ideas?
 
The point of this is to search absolutely everywhere. He isn't limiting us to where we can find it, as long as its not form another class-mate. We're allowed to use others as help.

I've been searching for awhile now =[
 
I've read theories about this, and usually discussions about this end up saying there's no real answer.

First one from http://www.mackido.com/Innovation/FileNames.html :
Because to do things (like copy a file), you had to type in the entire file name (and path name), people used lots of abbreviations and concatenation to reduce typing. This is why CP/M (DOS) used 8.3 (8 charaters + a 3 character suffix).

Second:
If you've come across with the name Gary Kildall during your research, count the letters in his name. This doesn't explain why it wasn't 7.4 though.

Third:
8.3, 8 + dot + 3 = 12 characters, compressed nicely with RAD50 into two words. However, CP/M does not compress filenames, and RAD50 was usually used to compress 6.3 or 9.3 filenames (some computers were 6-bit back then).

Fourth:
It comes from the 12 rows on an 80 column card. One row for each letter, plus the 12th row for a data clock (based on the stereotypical IBM 029 keypunch). A single column was punched in each row to mark the letter from the character set, yielding up to 80 choices per character.

Fifth:
There is evidence that Gary was one of those rare individuals with both DEC and IBM influences in his background. DEC had established the 3-character file extension as a standard on its systems, and IBM mainframes of the time had 8 characters as a common namespace size. Put the two together, and you get 8.3.

Sixth:
DEC's RT-11 used 8.3 filenames, and CP/M was developed using it as a guideline. This doesn't explain where RT-11 got 8.3 though.

Seventh:
Kildall chose 8.3 because he liked it.


So, which one do you choose?
 
Well, i gave him most of those and got:




So why did UNIX have it, with it being different all other OSes.

Some sound like you're just guessing. I consider only solutions, not guesses.
 
Another area to think about is the File Allocation Table, maybe that had something to do with it :)
 
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