CD Playthrough is a freeware program that allows you to set the Sound In and Playthrough options effortlessly. At last, you can enjoy audio CD's without an annoying and tedious trip to the Sound control panel.
Furthermore, CD Playthrough gives you the ability to dynamically switch between any of three input sources with or without playthrough, at the cost a few mouse clicks. This is extremely useful, even though the sound settings are now saved between reboots (Power Macs after System Update 3.0), since playthrough is disabled everytime you quit Video Monitor or FusionRecorder.
NOTE: you do *not* need an AV class or Power Macintosh to take advantage of CD Playthrough. If your computer is running Sound Manager 3.0 and the Sound control panel has the "Options..." button enabled in the Sound In pop-up, you can enjoy all of the features described below.
background
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Sound control panel 8.0.x was made more estensible and robust than its previous versions with Sound Manager 3.0. Unfortunately, this translated to some sacrifice in terms of convenience to the end user, audio CD playback on internal CD-ROM drives is a good example. You have to find and open the Sound control panel, select the Sound In pop-up, click the "Options..." button, pick the CD-ROM drive as source and finally check "Playthrough."
Those steps should not figure into anyone's idea of musical relaxation.
functionality
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That is where CD Playthrough comes in. When opened without holding down any of the special modifier keys, this tiny program attempts to directly set the input to the internal CD-ROM as well as turn on playthrough. If the Command key was held down, the program uses whatever is connected to the sound input port on the back of the Macintosh, microphone or external audio. If the Control or Option key were down, the AV Monitor input is used. If you don't have an AV Monitor, any modifier key will get you the microphone or external audio. Playthrough is enabled by default for all devices, turn on the Caps Lock to disable it.
CD Playthrough does have its limitations. It will not be able to change a locked sound input setting, such as when an AV Express Modem is active. This is actually a limitation of the Sound Manager, and currently there is no workaround. During these cases, until you turn off and/or quit the program that owns the lock, any human attempt to change the input results in this error message,
"The sound input device options cannot be accessed at this time."
If you launch CD Playthrough while the sound input settings are locked, it will simply beep once and quit without doing anything. For other generic errors (if no valid input devices, for example), the program will beep twice and quit. If you get repeated double beeps, you are probably missing the hardware or software needed for CD Playthrough. If this happens or anything else goes awry, I would appreciate and respond to any e-mail with details on your setup (CPU, CD-ROM hardware and software, System sound software, etc.)
That's the extent of the user interface, or the lack thereof. Should you ever forget the modifier keys and lose this Read Me, turn on Balloon Help over the program's icon for a short summary. And speaking of icons, they exist at both the regular and small sizes, perfect for the Apple Menu.
activities that lock the Sound In setting
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1) GeoPort Express Modem, actively dialing or connected
2) Sound Effects AND a Sound Out rate above 24.0 kHz
(Effects are only available to 68040-DSP AV's)
3) Video Monitor, FusionRecorder
?? Inform me if you find more
version history
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1.0 -- Public release:
Finalized this read me for Internet release, no code changes
0.3 -- Final release:
GetNextEvent() was used previously to detect modifier keys, but on Power Macs,
the modifier field of an event record is filled incorrectly. GetKeys() is
now used and has been tested to work on a Power Mac.
Used 'STR ' resource for Finder Balloon Help text message, was inlined in 'hfdr'
0.2 -- Beta release:
AV Monitor input support
Reduced memory allocation (64K->16K)
0.1 -- Developer release:
CD and microphone/external audio support
Error handling
Playthrough state (0-7) set to 100% of current sound volume
mumbo jumbo
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CD Playthrough is provided free of charge but remains copyright (1994) by jwang@soda.berkeley.edu <James Wang>. The complete archive, which must include this documentation, may be distributed freely, as long as it is not sold for profit and no part of the archive modified. This program is provided as is, with no warranty of any kind, expressed or implied. Though the chances are astronomically small, James and neg.active.productions cannot be held responsible for damages incurred from using CD Playthrough.
Developed using Symantec C++ 7.0.0, ResEdit 2.1.1, Resorcerer 1.2.
Tested on a Centris 660AV 16/230/CD running System 7.1 + SU 3.0.
Original code and additional testing thanks to anwyl@apple.com <Gary Anwyl>.
Products remain trademarks of their respective holders.
