[texhax] TeX Queries (1)

[Paul Stanley]

Hi folks
A few Tex queries from the TeXBook. I'm looking at the TeX source, 
however, you can download the PDF version at 
http://net.ytu.edu.cn/share/%D7%CA%C1%CF/texbook.pdf :

chapter 1, page 1, paragraph 1:
English words like `technology' stem from a Greek root <elipsis> 
which is an uppercase form of $\tau\epsilon\chi$.^^{TeX (actually 
\TeX), meaning of} ^^|\tau|^^|\epsilon|^^|\chi|

Does `^^{ ... }' signify a margin note?  I'm calling it a margine 
note because it appears separate from the main text on the right edge 
of the page.

I understand that in `^^|\tau|^^|\epsilon|^^|\chi|' each of the greek 
letters is displayed as a separate margin note.  What is the role of 
the `|' in the script?  I could be wrong, but it looks like a sort of 
flag for bypassing code that is enclosed within (`| ... |' ).  That 
said, what's interesting is that the `\' in `\tau', `epsilon' etc. is 
missing from the PDF.

paragraph 4:
On the other hand, it's important to notice <elipsis> 	other system 
names. In fact, ^{TEX} (pronounced <elipsis> processor developed by 
^{Honeywell Information Systems}. <elipsis> other medium that doesn't 
allow lowering of the `E', is to type `^|TeX|'. <elipsis>

I've also noticed that text preceded by just one `^' appears both in 
the paragraph where it's coded and as a margin note.  Is that the 
function of the single `^'?

chapter 2, page 3, paragraph 2:
In the first place, there are two kinds of <elipsis> that shows up as 
something like {\tt\char'22}, and an apostrophe or right-quote that 
looks like {\tt\char'15} or {\tt\char'23}.

`\char' according to some web sources maps numeric values to their 
corresponding unicode characters.  in the above extract the macro is 
separated from the numeric value by an apostrophe. I've seen both a 
grave accent (`) and a double quote mark (") used in examples on the 
web. Do the symbols declare different things about the number that 
follows them?

finally, what's the difference between `\eject' and `\vfil\eject'?  I 
understand `\ject' forces a page break.  A `\vfil' prefix I hear 
improves/mitigates the visual effect of `\ject' in certain 
circs.  Unfortunately, the text doesn't explain exactly what form the 
improvmenet takes.  Any clues would be appreciated.

Many thanks,
Paul