Re: Frob Linux Control Port Register

On Mon, 20 Aug 2007, in the Usenet newsgroup comp.os.linux.embedded, in article
<1187623734.718137.202530@xxxxxxxxxxxxxxxxxxxxxxxxxxx>, Philbo30 wrote:

Hopefully this is the right group; what exactly is meant by "frobbing"
the Linux parallel port control register?

See if you can find a copy of Eric S. Raymond's "Jargon File". In there,
you will find:

========================================================================
:bit twiddling: n.
3. Approx. syn. for {bit bashing}; esp. used for the act of frobbing
the device control register of a peripheral in an attempt to get it
back to a known state.

:frob: /frob/

1. n. [MIT; very common] The {TMRC} definition was "FROB = a
protruding arm or trunnion"; by metaphoric extension, a frob is any
random small thing; an object that you can comfortably hold in one
hand; something you can frob (sense 2). See {frobnitz}.

2. vt. Abbreviated form of {frobnicate}.

3. [from the {MUD} world] A command on some MUDs that changes a
player's experience level (this can be used to make wizards); also,
to request {wizard} privileges on the `professional courtesy' grounds
that one is a wizard elsewhere. The command is actually `frobnicate'
but is universally abbreviated to the shorter form.

:frobnicate: /frob´ni·kayt/, vt.

[Poss. derived from {frobnitz}, and usually abbreviated to {frob},
but frobnicate is recognized as the official full form.:] To
manipulate or adjust, to tweak. One frequently frobs bits or other
2-state devices. Thus: "Please frob the light switch" (that is, flip
it), but also "Stop frobbing that clasp; you'll break it". One also
sees the construction to frob a frob. See {tweak} and {twiddle}.

Usage: frob, twiddle, and tweak sometimes connote points along a
continuum. `Frob' connotes aimless manipulation; twiddle connotes
gross manipulation, often a coarse search for a proper setting; tweak
connotes fine-tuning. If someone is turning a knob on an
oscilloscope, then if he's carefully adjusting it, he is probably
tweaking it; if he is just turning it but looking at the screen, he
is probably twiddling it; but if he's just doing it because turning a
knob is fun, he's frobbing it. The variant frobnosticate has been
recently reported.

:frobnitz: /frob´nits/, pl., frobnitzem, /frob´nit·zm/, frobni,
/frob'ni:/, n.

[TMRC] An unspecified physical object, a widget. Also refers to
electronic black boxes. This rare form is usually abbreviated to
frotz, or more commonly to {frob}. Also used are frobnule
(/frob´n[y]ool/) and frobule (/frob´yool/). Starting perhaps in 1979,
frobozz /fr@-boz´/ (plural: frobbotzim /fr@-bot´zm/) has also become
very popular, largely through its exposure as a name via {Zork}.
These variants can also be applied to nonphysical objects, such as
data structures. For related amusement, see the Encyclopedia
Frobozzica.

Pete Samson, compiler of the original {TMRC} lexicon, adds, "Under
the TMRC [railroad] layout were many storage boxes, managed (in 1958)
by David R. Sawyer. Several had fanciful designations written on
them, such as `Frobnitz Coil Oil'. Perhaps DRS intended Frobnitz to
be a proper name, but the name was quickly taken for the thing". This
was almost certainly the origin of the term.
========================================================================

My initial interpretation is that it may be the process of sending
"0x04" to the register to drive pins 1, 14,16,17 tty high. Is that
correct?

That would fit the third definition of "bit twiddling", though I'm not
sure of the exact bits to send to the register.

Old guy
.