| ★ APPLICATIONS ★ DIVERS ★ RSX - SOUND ENVELOPE DESIGNER (POPULAR COMPUTING WEEKLY) ★ |
Sound Envelope Designer (1986-06-12) | Sound Envelope Designer (1986-06-19) |
This week sees the second and final helping of listing for the Sound Designer program we started last week. As explained before, the utility is fully icon driven and very easy to use Files are loaded into the sound designer by selecting the Load option Any envelope not included in the file being loaded will not be affected - therefore liles can be merged into the designer from various different files if required Selecting the Disc icon (which will only operate if you have a disc drive connected), will produce the same menu as for tape, allowing loading and saving of files to disc An additional option is Directory. which will display the filenames of all Env files on the disc. The penultimate icon shows a fat cross X' - selecting this allows you to clear the entire current envelope settings Select 'Yes'to go ahead, or No" to cancel the command. Clearing the envelope wipes out the volume graph and resets the vibrato settings. Only the current envelope is cleared, all others remain unaffected. The final icon shows a left pointing arrow, this is used for deleting the last section of the current volume envelope entered on to the graph. If no sections have been entered then the command is ignored. Attempting to add more than five sections on to the volume graph will produce an error message and will be ignored, as will attempting to add a section that goes 'backwards'in time. A little experimentation with this program can create some quite impressive results which, when combined into your own programs, could have your Amstrad sounding like a small orchestra (maybe). For those interested in the workings of the program, the various subroutines and key sections of code have been fully commented. The small section of machine code at the start of the program is used to produce the small arrow which moves in response to your joystick; you will find it produces a smooth and flicker free pointer. The routine exits to Basic when the joystick fire button is pressed Owners of an AMX Mouse for their Amstrad may like to know that the program will work equally well with this, rather than a joystick, without modification - you do not need to load any other software first. Whenever a new volume envelope section is added, the program automatically works out the best fit' line which will produce the correct volume change over the required time. It is only limited by the Amstrad's sound hardware. The usual technique is used for checking for the presence of a disc system. This involves setting an On Error trap and calling the I Disc command. If this command exists then no error will occur and a disc system is present. If it does not exist then an 'Unknown command'error will be caught and the program will note that no disc system is present and default to tape. All sound designer files are simple Ascii files which contain Basic compatible Env and Ent commands on separate lines starting at Line 500 in steps of ten. The program checks for syntax errors when loading in a file and will abandon the load if any are noted - this will only occur if you attempt to load in files which have not been produced by the Sound Designer. PopularComputingWeekly |
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