Pro Tracker 3.51 player fix

Hello, All! How to fix Pro Tracker 3.51 player so that commands 9 and A, that change the frequency of the envelope were processed correctly. The source text of the player contains the following fragment: ;--- install_E --- E_ins0 JR Ei_form Esl_ids LD HL,0 ;stp_sld_env LD (Esl_sds+1),HL Esl_ist LD A,0 ;stp_sld_p LD (Esl_stp+1),A <──────────────────────────── (1) LD (Esl_sts+1),A LD A,#18 LD(E_ins0),A Ei_form LD A,0 ;env_form LD(E_form+1),A AND A JR Z,temp Ei_frq LD HL,0 ;env_frq LD (E_frq+1),HL XOR A LD L,A LD H,A LD(Ei_form+1),A LD (Esl_stp+1),A <──────────────────────────── (2) LD (Esl_frq+1),HL What do we see? (1) - to a variable at Esl_stp+1 one of the command parameters 9 or A is placed. Next, if this the command was on a note using the envelope (i.e. Ei_form+1 not 0), then a program fragment containing (2) is executed - Resetting the Esl_stp+1 variable to zero. The command parameter is reset to zero - and as a result there will be no change in frequency of the envelope. How to fix it? The recipe I gave in the description previous version of BestView (byte reset at offset #4C1 fromstart of the player), actually canceled the command (2). At the same time commands 9 and A started to work, but did not finish changing frequency when the next note using envelope. So some modules still sounded wrong. For a final fix, a fragment of the player needs to be change it like this: ;--- install_E --- E_ins0 JR Ei_form Esl_ids LD HL,0 ;stp_sld_env LD (Esl_sds+1),HL Esl_ist LD A,0 ;stp_sld_p LD (Esl_stp+1),A LD (Esl_sts+1),A LD A,(Ei_form+1) AND A JR Z,BUG_F3 LD A,#3E LD(BUG_F2),A BUG_F3 LD A,#18 LD(E_ins0),A Ei_form LD A,0 ;env_form LD(E_form+1),A AND A JR Z,temp Ei_frq LD HL,0 ;env_frq LD (E_frq+1),HL XOR A LD L,A LD H,A LD (Esl_frq+1),HL LD(Ei_form+1),A BUG_F2 JR BUG_F1 LD A,#18 LD(BUG_F2),A JR temp BUG_F1 LD (Esl_stp+1),A Please note that the length of the player is slightly will increase. Best regards, Ivan Roshchin.