Clamp pitch and hi-pitch envelope period results

Source/drivers/asm/effects.s

@@ -517,27 +517,28 @@ ft_portamento_up:
 	sta var_Temp16
 	lda #$00
 	sta var_Temp16 + 1
+.if .defined(USE_N163)
+    lda ft_channel_type, x
+    cmp #CHAN_N163
+    bne :+
+    ; Multiply by 4
+    asl var_Temp16
+    rol var_Temp16 + 1
+    asl var_Temp16
+    rol var_Temp16 + 1
+:
+.endif
 	jsr ft_period_remove
 	jsr ft_limit_freq
-:	jmp ft_post_effects
+	jmp ft_post_effects
 ft_portamento_down:
 	lda var_ch_Note, x
 	beq :+
 	lda var_ch_EffParam, x
 	sta var_Temp16
 	lda #$00
 	sta var_Temp16 + 1
-	jsr ft_period_add
-	jsr ft_limit_freq
-:	jmp ft_post_effects
-
-ft_period_add:
 .if .defined(USE_N163)
-.if .defined(USE_LINEARPITCH)		;;; ;; ;
-	lda var_SongFlags
-	and #FLAG_LINEARPITCH
-	bne :+
-.endif								; ;; ;;;
     lda ft_channel_type, x
     cmp #CHAN_N163
     bne :+
@@ -548,6 +549,16 @@ ft_period_add:
     rol var_Temp16 + 1
 :
 .endif
+	jsr ft_period_add
+	jsr ft_limit_freq
+	jmp ft_post_effects
+
+ft_period_add:
+.if .defined(USE_LINEARPITCH)		;;; ;; ;
+	lda var_SongFlags
+	and #FLAG_LINEARPITCH
+	bne :+
+.endif								; ;; ;;;
 	clc
 	lda var_ch_TimerPeriodLo, x
 	adc var_Temp16
@@ -561,26 +572,12 @@ ft_period_add:
 	sta var_ch_TimerPeriodHi, x
 :   rts
 ft_period_remove:
-.if .defined(USE_N163)
 .if .defined(USE_LINEARPITCH)		;;; ;; ;
 	lda var_SongFlags
 	padjmp_h	8
 	and #FLAG_LINEARPITCH
 	bne :+
 .endif								; ;; ;;;
-    lda ft_channel_type, x
-    cmp #CHAN_N163
-	padjmp		7
-	padjmp_h	4
-    bne :+
-    ; Multiply by 4
-    asl var_Temp16
-    rol var_Temp16 + 1
-    asl var_Temp16
-	padjmp		5
-    rol var_Temp16 + 1
-:
-.endif
 	sec
 	lda var_ch_TimerPeriodLo, x
 	sbc var_Temp16

Source/drivers/asm/instrument.s

@@ -179,20 +179,22 @@ ft_run_instrument:
 	jsr ft_translate_freq_only
 
 	; Check this
-:	clc
-	lda var_sequence_result
-	adc var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodLo, x
+:	lda #$00
+	sta var_Temp16 + 1
 	lda var_sequence_result
-	bpl @NoNegativePitch
-	lda #$FF
-	bmi @LoadLowPitch
-@NoNegativePitch:
-	lda #$00
-@LoadLowPitch:
-	adc var_ch_TimerPeriodHi, x
-	sta var_ch_TimerPeriodHi, x
-	jsr ft_limit_freq
+    sta var_Temp16
+	bpl @PositivePitch
+@NegativePitch:
+    ;; !! !! change the sign
+    lda #$FF
+    eor var_Temp16
+    sta var_Temp16
+    inc var_Temp16
+	jsr ft_period_remove
+	jmp :+
+@PositivePitch:
+	jsr ft_period_add
+:	jsr ft_limit_freq
 	; ^^^^^^^^^^
 
 	; Save pitch
@@ -211,32 +213,39 @@ ft_run_instrument:
 	sta var_ch_SequencePtr4, x
 
 	; Check this
-	lda var_sequence_result
-	sta var_Temp16
-	rol a
-	bcc @AddHiPitch
-	lda #$FF
-	sta var_Temp16 + 1
-	jmp @StoreHiPitch
-@AddHiPitch:
 	lda #$00
 	sta var_Temp16 + 1
-@StoreHiPitch:
+	lda var_sequence_result
+	sta var_Temp16
 	ldy #$04
 :	clc
-	rol var_Temp16 						; multiply by 2
+	rol var_Temp16 						; multiply by 16
 	rol var_Temp16 + 1
 	dey
 	bne :-
 
-	clc
-	lda var_Temp16
-	adc var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodLo, x
-	lda var_Temp16 + 1
-	adc var_ch_TimerPeriodHi, x
-	sta var_ch_TimerPeriodHi, x
-	jsr ft_limit_freq
+	lda var_sequence_result
+	bpl @PositiveHiPitch
+@NegativeHiPitch:
+    ;; !! !! change the sign
+    lda #$FF
+    eor var_Temp16 + 1
+    sta var_Temp16 + 1
+    lda #$FF
+    eor var_Temp16
+    clc
+    adc #$01
+    sta var_Temp16
+    lda #$00
+    adc var_Temp16 + 1
+    sta var_Temp16 + 1
+	jsr ft_period_remove
+    ; check for over/underflow
+    ; limitperiod()
+	jmp :+
+@PositiveHiPitch:
+	jsr ft_period_add
+:	jsr ft_limit_freq
 	; ^^^^^^^^^^
 
 @SkipHiPitchUpdate:

Source/drivers/asm/player.s

@@ -1595,11 +1595,11 @@ ft_limit_note:		;;; ;; ;
 ;	pla
 	cpx #APU_NOI
 	beq :+++
-	cmp #$00
+	cmp #$00	; no note
 	beq :+
 	bpl :++
 :	lda #$01
-:	cmp #$60
+:	cmp #$60	; note 95 (incremented by one earlier)
 	bcc :+
 	lda #$60
 :	rts				; ;; ;;;