Tune-a-Fish

TUNE-A-PATE


from Your Sinclair #10 (Oct.1986)





You want to add tasty machine code music to your own games?


Well, open a tin of Tune-A-Fish in the company of this


month's Master Chef Benny Modig, and see how easy it can be.








If you ever thrilled to the music on your Spectrum computer


games, and wondered if your games could sound as tuneful,


then this is the recipe for yoo-hoo! You see, the reason


you're so incredibly gripped, excited and thrilled by the


music in professionally produced games is this: the tunes


are stored in machine code in a space in the computer's


memory and riffed through jolly fast by a miniature reading


routine.





Contained within this awfully short program are all the


necessary doobries to add your music to your own games


without interrupting the action! You can compile the code of


your music to anywhere in memory, so that it fits in with


any programming needs. Also, it's only 189 bytes long, so


it'll work with quite long programs.





The drawback of using sound with Spectrum programs has


always been that in order to generate the sound, the


computer has to stop processing. This lasts for the duration


of the sound which in some cases could be a whole second,


making arcade action very slow indeed. The great strength of


this program is that it holds up the program in operation


for only about (set at top speed) 0.01 of a second to make


your sound effects and musical tones. So, this is one dish


you can't afford not to serve in your Spectrum!








WHAT TO DO





First wash your hands and lay out all the ingredients on a


clean work surface. Spread a little butter on the bread and


pile Tuna on one slice. Press the other slice on top of all


this and eat. Hurry up, there's work to do! Nice? You bet.


Okay, down to business ...





Type in the program as listed (a Tried'n'Tested product) and


save it to tape as SAVE "TUNE-A-FISH' LINE 1. Now, all you


need to add music to your programs is together in one


ready-to-serve portion. After running the program you are


faced with the main menu.








STARTERS





C Changes the speed of the piece of music


O Gets you out of the program


S Saves your compiled tune


L Listen to your tune


K Compiles your tune to mega quick code








SERVING SUGGESTIONS





Mmmm. There are so many tasty ways you can enjoy your


Tune-A-Pate. There are a couple of limitations to the


program, but with careful programming and a bit of


forethought, these problems can be overcome.





The number of notes you can compile at one time is limited


to 17 maximum. If the tune you want to compile is longer


than this, and what tune isn't, you can do the following:





Put the tune in groups of 17 notes in DATA statements at the


beginning, in the same way as the demo tunes, with a REM


command before them. Remove the REM from a line and compile


it to your first block of memory. Then put the REM back and


remove the next line's REM and compile that to the next


address after the last piece you compiled. (Got that?)


Repeat the procedure until all your notes have been


compiled. You call back the routine with LET I=USR adr1: LET


I=USR adr2: ... and so forth, where adr is the address where


you put the notes.





Tune-A -Pate is so versatile. With thoughtful programming,


and a little knowledge of the BEEP command, you can not only


program tunes into your games, but also superfast sound


effects which don't interrupt the action. Now there's a


herring sandwich.








Lines 2-4 These are the demo tunes stored in REM statements


to illustrate the method of inputting notes to the


compiler.


Line 5005 Here the SAVE routine is shown as a microdrive routine,


but if you want it to work with tape, simply delete


the *"M";1; parts of the line.


Line 6000 The Listen routine, including a moving asterisk to


show that the delay is always the same.


Line 8901 The machine code interrupt and controller program.


Lines 9002-9003 A table of note frequencies to make the notes you hear


closer to real musical pitches.








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Another Fine Product transcribed by:


Jim Grimwood (jimg@globalnet.co.uk), Weardale, England


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