From: kanefsky@halcyon.com (Steve Kanefsky)
Subject: Re: Let's talk Performas, Boys and Girls
Organization: The 23:00 News and Mail Service
Date: Thu, 1 Oct 1992 21:43:32 GMT

In article <1992Oct1.193534.5212@dartvax.dartmouth.edu> hades@Dartmouth.Edu writes:
>daver@ux1.cso.uiuc.edu (David Ruby) writes:
>>hades@coos.dartmouth.edu (Hades) writes:
>
>>>    There is no sound-out port on either the Plus or the SE.
>>>    Well, the SE/30, IIcx and IIci do not have sound-out ports. But for
>>>the others, there is a sound out port. 
>
>>I'm sitting next to a SE/30, and actually using a IIci that have what
>>look like headphone jacks on the back with a little sound icon above
>>it.  I'm pretty sure my SE at home has this too.  
>>Are these not sound-out ports?  If not, what are they for?  I've
>>never used them, but felt warm inside knowing I could hook up stereo
>>speakers to them at a later date if I wanted.
>
>    Yeah, I knew I wasn't making myself clear about this, sorry for
>that. Yes there is a headphone jack on the older macs, and I'm pretty
>sure that it is a mono output jack that works just like the internal
>speaker. What I should have been saying was that these macs, with the
>headphone jacks, do not have direct sound-in ports as thoush macs with
>microphones do. And while it is possible to connect a set of speakers to
>the headphone jack, it is not a stereo sound-out port.
>
>>>    All macs introduced since the IIsi and the LC have the same sound
>>>capabilites, mono input and stereo output.
>
>>I've never used either, so I'm curious.  Does this mean there are two
>>speakers and games or other cleverly written software will do real
>>stereo sound (cool echoes, etc)?  
>
>    No. See I was still not making myself clear... All of the macs that
>come with a microphone have ports for mono sound input and stereo sound
>output.  They only come with one internal speaker (mono only,
>obviously), so if you have a game with stereo sound and you want to take
>advantage of this you will need to connect stereo speakers to the
>sound-out port.
>    I hope this makes a little more sense, and I'm pretty sure that what
>I have stated above is correct, or at least this is what I remember from
>readin all of those write-ups and spec sheets when the "sound capable
>macs" were introduced.

I think you're still not getting it right.

Every Mac II and Quadra, plus the SE/30 have a 1/8" walkman-type 
*STEREO* sound-output port.  This is completely independent of the   
sound-input port.  There are Macs that have sound input but not
stereo output (e.g. Mac LC/LC II) and there are Macs that have
stereo output but no sound input (e.g. Mac IIci).

*Every* Mac has a sound output port.  It's just that only the
above-mentioned models have *stereo* output.  Even the original 128K    
Mac which I bought in 1984 had one.  I know that the newer models
with mono ouput are wired such that the mono output is duplicated in  
each stereo channel, so you won't get sound in just one speaker if
you plug in stereo headphones.  I'm not positive whether the older
each stereo channel, so you won't get sound in just one speaker if
you plug in stereo headphones.  I'm not positive whether the older
models did that.  I think they've also reduced the output level on  
the newer models to be more compatable with walkman headphones.  The
early Macs would blow your eardrums off if you plugged-in headphones
without some sort of attenuator.

Even with the stereo output port on the higher-end Macs, the last I 
heard (which was a while back) the System software didn't support
stereo, so there are very few programs which actually produce stereo
sound effects.
  
  
--
Steve Kanefsky


Newsgroups: comp.sys.mac.hardware