Re: Some IIgs questions

[Rubywand <rubywand@swbell.net>]

MQSmith writes ...
> 
 ....
> 
> Near the back of the case, near the expansion slots, there is a what
> appears to be a power hookup labeled 'FAN', with two pins extending out
> of a red plastic casing.  I'm assuming that this is a hookup for a fan
> (unless it's some acronym).  If it is, what's the voltage and where
> would I put the actual fan?
>

     It's for an optional 12V DC fan which attaches to the power supply. Most
users do not add this fan because it adds noise (including electrical circuit
noise) and does not do much for cooling the GS. (Our IIgs uses the original
power supply which has never had a fan attached to it.)

     The most popular IIgs cooling accessory is the "System Saver IIgs". This
is a thin 'power center' type module designed to look like part of the GS and
sit on top. It gives you line deglitching, some power outlets in the back, and
a couple power switches. For cooling, it includes a fan which pulls air through
the computer and up through the lid. 

 
> At the beginning of the motherboard, to the left of a power hookup (a
> wire runs from it underneath the motherboard to the speaker), there's
> something that looks like a larger power hookup.  It has a red casing
> the same color as the other ones, but it is larger and has seven pins,
> not just two.  What is this, and what is it for?

     This sounds like the J25 connector (right-front corner of motherboard,
just to the left of the Spkr. connector).  J25 has sound output and input
lines. It mainly supplies multiplexed sound output signals to an optional
"Stereo Card". It includes an input for digitized sound from a separate
digitizer card or Stereo Card with digitized sound input.

     For more about IIgs sound stuff, see Csa2SOUND.txt on one of the FAQs
sites:

Ground offers pure Text for downloading or Viewing via an FTP program ...
  ftp://ground.ecn.uiowa.edu/apple2/Faqs/
 
Text on the ACN Florida, ACN Tarnover, and USA2WUG sites is
 line-length formatted for on-line perusing via Netscape, etc. ...
 
  ftp://24.96.48.134:6502/Cabi_Archives/FAQs.and.INFO/A2.Csa2.FAQs/
  ftp://tarnover.dyndns.org/cabi/FAQs.and.INFO/A2.Csa2.FAQs/
  http://www.grin.net/~cturley/A2.FAQs.and.INFO/CSA2.FAQs/

Or, the web page at http://home.swbell.net/rubywand/Csa2SOUND.html



 ....
> Is there a site I could go to that has schematics for all the stuff on
> the motherboard, explaining what each thing does?  I'd like to take a
> look at one if only to satisfy my curiosity.
 ....

     Don't recall coming across schematics for any IIgs model on-line on the
net. The Apple IIgs Hardware Reference, second edition has schematics for both
popular versions.

     You can get some getting started IIgs info at one of the sites listed
earlier (see the Csa21MAIN file) and at ...

http://home.swbell.net/rubywand/A2FAQs5MAINHALL.html

Gabriel Morales's Apple II Beginner's Guide at 
http://www.concentric.net/~Togega/Apple2/ 

Terry Allen's Home of the Apple II at 
http://www.educate.net.au/~apple2/

And, for some beginning IIgs manuals, see
http://www.educate.net.au/~apple2/manuals/index.html


     You can find a large collection of IIgs information on the 
Apple Cabi.net archives at
Florida- ftp://24.96.48.134:6502/Cabi_Archives/FAQs.and.INFO/ 
Tarnover- ftp://tarnover.dyndns.org/cabi/FAQs.and.INFO/ 



Rubywand