re stereo sound problem on mac games in article qsfak skc network ucsd edu doug p book dpb sdchemw ucsd edu writes hi i think i have a problem with the stereo sound output on my quadra but i am not totally sure because my roomate has the same problem on his powerbook any info or experience anyopne has would be greatly appreciated when i hook my quadra up to my home stereo system the following types of sounds mono as far as i can tell all play fine through both speakers system beeps already provided ones such as indigo and ones i record armor alley spectre spaceward ho but the following games only play out of the left channel lemmings out of this world awesome game btw glider oids but still stereo system beeps do play in stereo through both speakers the one i m specifically referrring to is apocolyptic beginning which my roommate downloaded from some ftp site sumex all of the symptoms are the same on my rommates he can t run ootw because he doesn t have color we re both running system does anyone with lemmings or the other three games i mentioned above get sound out of both speakers on a mac ii class quadra lc powerbook or greater centris se etc stereo machine i used to have a mac ii and i sort of rememeber lemmings playing in stereo on that machine not just on the left channel i could be mistaken though if there were a problem with the quad s and pb s i am wondering why the system beeps still play in stereo if there isn t a problem with our machines i wonder why the games above are apparantly written to support only one channel of stereo when they could just use mono sounds so the mono sound would at least come out of both speakers like spectre etc do quadra s and powerbook s have the same roms to my knowledge so maybe this is a rom problem if so though why wouldn t system patch over this problem thanks for any help you can provide in article apr kth se jon wtte d jwa hemul nada kth se writes mac sound hardware is diverse some macs play in stereo and mix the output the se for instance while others play in stereo but only has the left channel for the speaker while some are truly mono like the lc developers know that stuff played in the left channel is guaranteed to be heard while the right channel isn t some send data to both some only send data to the left channel the first is preferrable of course okay i guess its time for a quick explanation of mac sound the original documentation for the sound hardware im documents how to make sound by directly accessing hardware basically you jam values into all the even bytes from soundbase to soundbase x this was because of how the mac and some later machines generated sound was by scanning this block and d aing every even byte the odd bytes went to the floppy on some machines when the mac ii and apple sound chip was invented it was designed to generate stereo sound it was also designed to be compatible with we had once documented so storing bytes at the even values at soundbase meant i want to play a mono sound and so it was emulated but apple had since retracted the documentation on soundbase and decided not to document the lowest layers of sound generation so apple never explained where to stuff bytes if you want to make stereo sound enter game developers the sound driver and current sound manager are inconveniently lame for making games furthermore people who port from the ibm don t want to learn more apis so it has become popular for game writers to write to soundbase to make sound since it is very easy since the mac ii apple has had many different kind of sound output hardware and the only things they have in common are that writing to soundbase works on some hardware mac ii iix iicx iici at least writing to soundbase gets you mono sound through both speakers on some macs quadra at least writing to soundbase gets you mono sound on the left channel only both are technically correct interpretations of the original specification but one is obviously preferable for asthetic reasons if developers use the sound manager and i think the sound driver mono sounds will typically come out through both channels regardless of the underlying hardware it is possible to specify you want to generate left channel only but no one does if developers write to sound base their games will only come out the left on some games the other problem the original mac ii only producing left channel sound on the internal speaker while the se mixes both isn t really related it is due to the post generation amplification used on the motherboards of the different machines it only affects true stereo sounds sounds which are actually mono will play on the internal speaker no matter what machine you have now to more directly address the question the games you list lemmings out of this world awesome game btw glider oids and also hellcats super tetris oxyd and many more these are just what i ve tested cheat and write to soundbase and so are only left channel on quadras other games you list armor alley spectre spaceward ho and also pga tour golf civilization and more these are again only from personal experience use the sound manager and work fine on all machines the more of the story is to developers don t cheat really i am absolutely positively not allowed to do what i am about to do but i m going say it anyway stop cheating on sound really soon you will be sorry as even those without external speakers will be disappointed with your sound on future hardware the grace period is about to end the sound manager is understandable now and works pretty well and will work even better soon so use it in conclusion to doug it isn t a hardware problem at least not a bug to jon it isn t a choice to developers as to whether they want to send sound to both channels if they do it the right way it is taken care of automatically if you cheat there is not way to make it work on all hardware have fun disclaimer number i don t work on sound here at apple i m just pretty well informed so don t write me with sound questions disclaimer number if it says up above that i wrote anything like the grace period is about to end then it is a bug in your news feed since i am catagorically not allowed to say anything like that you know what i mean disclaimer number i don t speak for apple just me steve bollinger
