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1、pc系列机的发音方法（PronunciationmethodofPCseriesmachine）ThepronunciationmethodofPCseriesmachine1991-12-27Atimer,thevoicecontrolchipProgrammabletimerchipisthecoreofthestandardPCsoundproductionfunction.Thechannel2ofthetimerchipisdedicatedtosoundproduction.Toproduceasound,t
2、hechannel2mustbeproperlyprogrammedandusedtodrivethespeakerusingpulsesfromchannel2.TheByprogrammingthetimercanbeinanyneedtosendoutpulsefrequency,butbecauseitdoesnotsoundrecordinglastedlong,unlessitisclosed,otherwisethesoundwillcontinueforever;therefore,theprogramm
3、ustthroughsomeinstructionstostopsoundingtiming.The1,thetimerprogrammingchip."Thetimerchannel2programming,channel2tocounterasuitablenumerical(countdowntimerchipwithaninternalregistertoholdthevalue,sothateverytimethecountercountsdownto0whenresettingthecount).Thecou
4、ntdowntimerchipinthenumericalloadimmediatelyplayarole.Ineach1.19318MHzclockcycle,thetimerdecrementsthiscounteruntilitisreducedto0,andthenthepulseisoutputonthechannel2totheaudiogeneratingcircuitandthecountbeginsagain.TheInfact,thefrequencyoftheclockiscounted(i.e.,
5、theinitialvalueoftheinvertedcount),inadditiontotheoutputfrequency.Asaresult,ifthespeakeristurnedon,thetimersendsoutaseriesofpulsestoproduceacertainfrequencyofsound.TheTherelationshipbetweenthefollowingformulacountandfinalfrequency:theThecountof=1193180dividedbyth
6、efrequencyThefrequencyof=1193180,thecountvalueItcanbeseenthathighnumericalvaluesproducelowfrequencysounds,whilelownumericalvaluesproducehighfrequencysounds.Acountof100producesahighfrequencyofabout11931cyclespersecond,withavalueof10000,producingabasswithafrequency
7、ofabout119cyclespersecond.TheAlmostanyfrequencycanbegeneratedintherangeof16bitsofarithmetic.Whenthedivisor(thatis,thefrequencydivision)is65535(FFFFH),thelowestfrequency18.2Hzisgenerated,andthehighestfrequency1.193MHzisgeneratedwhenthedivisoris1.BASICcontrolstheac
8、tualfrequencyrangefrom37to3276Hz.ThefollowingproceduresshowthattheactualfrequencyrangeoftheinternalspeakersisevensmallerthanthatprovidedbyBASIC.TheOnceyouhavec
