p0TP            p0TP                      Ever  since  buying  our  first   (of   several)   Atari          computers, an Atari 800, many years ago, I have enjoyed using          our computers to make music.  I  bought  many  of  the  music          programs for the 8-bit Atari's, and after buying  our  520ST,          added a Roland synthesizer and Yamaha tone generator  because          of the ST's excellent MIDI capabilities. I  even  bought  the          MIDI-MATE interface from Hybrid Arts (so  that  the  old  800          would not feel left out).               When the December 1988 copy  of  ANTIC  arrived  in  the          mail, I immediately went out and bought the disk version,  to          get a copy of the ANTIC MUSIC PROCESSOR (AMP from now on).  I          tried it and liked it, and so I proceeded to convert many  of          my  AMS  II  files  using  the  supplied  converter  program.          However, several problems quickly came to light. Since it  is          written in Basic, it is quite slow  of  course.  Some  of  my          files are quite large, and my patience started to wear  thin.          Also, it had problems with files which did  not  include  all          four  voices  (a  minor  bug  which   was   easy   to   fix).          Unfortunately, a more serious problem quickly became evident.          It did not handle AMS tempo values properly at all. It simply          divided them by 5, like it did the durations for notes.  This          does not work right at all, and produced meaningless  tempos.          It was time to fix these problems, so I pulled out my Action!          cartridge and started coding.               A while back, I had written  several  similar  programs,          also in Action!, to convert AMS files  to  other  formats.  I          used one of these  as  a  model,  and  quickly  had  AMSTOAMP          working.   It   even   converted   AMS   tempos   accurately.          Unfortunately, AMP itself does not deal with tempos properly.          If you take an AMS song and plot a  graph  of  elapsed  times          versus various tempos, you get the expected exponential curve          (double the tempo, halve the time; double it again, and halve          the time again). If you do the  same  with  AMP,  you  get  a          straight line graph. This means that my converted AMS  tempos          did not work out right at all. Some  songs  played  too  fast          while others played too slow. I fixed this in my  program  by          adding a conversion table, mapping the AMS  tempos  to  tempo          numbers which seemed to work out in AMP  (most  of  the  time          anyway).               The program was now working just  fine.  I  used  it  to          convert all my better AMS II files, with excellent results. I          even ran one of my earlier programs to convert many excellent          AMS (the original program from APX) files to AMS  II  format,          and then further converted them to AMP, again with  excellent          results. I hope that the program will work out  as  well  for          you as it did for me.