Start to change the sound code to wait for the doc to be free and to write and then read to verify that the register write succeeded or try again. That seems to cleanup the sound on real HW. I have only done this for the bonus and the firing sound but probably all register writes should be done this way.

BuGS.xcodeproj/xcuserdata/jrand.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -7,7 +7,7 @@
 		<key>Binary.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>3</integer>
+			<integer>2</integer>
 		</dict>
 		<key>BuGS.xcscheme_^#shared#^_</key>
 		<dict>
@@ -17,12 +17,12 @@
 		<key>DiskImage.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>2</integer>
+			<integer>1</integer>
 		</dict>
 		<key>doNotBuild.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>1</integer>
+			<integer>3</integer>
 		</dict>
 	</dict>
 </dict>

BuGS/gameSound.s

@@ -108,6 +108,27 @@ SCORPION_FREQ_LOW	equ 214
 SCORPION_CONTROL	equ SOUND_SWAP_MODE
 SCORPION_SIZE		equ $2d
 		
+	
+; Y has the register to write to (16 bit mode)
+; A has the value to write (8 bit mode)
+; Assuming not in increment mode
+writeReg entry
+		sta registerValue
+writeReg_loop anop
+		tya
+		sta >SOUND_ADDR_LOW
+		_docWait
+		lda registerValue
+		sta >SOUND_DATA_REG
+		tya
+		sta >SOUND_ADDR_LOW
+		_docWait
+		lda >SOUND_DATA_REG
+		lda >SOUND_DATA_REG
+		cmp registerValue
+		bne writeReg_loop
+		rts
+
 		
 soundInit entry
 ; Spider sound
@@ -641,31 +662,28 @@ playBonusSound entry
 		short m
 		lda >SOUND_SYSTEM_VOLUME
 		and #$0f
-		ora #$20
 		sta >SOUND_CONTROL_REG
 		
-		lda bonusSoundOscReg
-		sta >SOUND_ADDR_LOW
-		lda #BONUS_CONTROL+SOUND_HALTED+SOUND_RIGHT_SPEAKER
-		sta >SOUND_DATA_REG
+		_writeReg bonusSoundOscReg,#BONUS_CONTROL+SOUND_HALTED+SOUND_RIGHT_SPEAKER
+		iny
 		lda #BONUS_CONTROL+SOUND_HALTED+SOUND_LEFT_SPEAKER
-		sta >SOUND_DATA_REG
+		jsr writeReg
 		
 		lda bonusSoundOscReg
 		and #$1f
 		ora #SOUND_REG_VOLUME
-		sta >SOUND_ADDR_LOW
+		tay
+		lda tileRightVolume,x
+		jsr writeReg
+		iny
 		lda tileRightVolume,x
-		sta >SOUND_DATA_REG
 		eor #$ff
-		sta >SOUND_DATA_REG
+		jsr writeReg
 		
-		lda bonusSoundOscReg
-		sta >SOUND_ADDR_LOW
-		lda #BONUS_CONTROL+SOUND_RIGHT_SPEAKER
-		sta >SOUND_DATA_REG
+		_writeReg bonusSoundOscReg,#BONUS_CONTROL+SOUND_RIGHT_SPEAKER
+		iny
 		lda #BONUS_CONTROL+SOUND_LEFT_SPEAKER
-		sta >SOUND_DATA_REG
+		jsr writeReg
 		long m
 		
 		lda bonusSoundOscReg
@@ -758,31 +776,25 @@ playKillSound entry
 
 playFireSound entry
 		short m
+		_docWait
+		
 		lda >SOUND_SYSTEM_VOLUME
 		and #$0f
-		ora #$20
 		sta >SOUND_CONTROL_REG
 		
-		lda #SOUND_REG_CONTROL+FIRE_OSC_NUM
-		sta >SOUND_ADDR_LOW
-		lda #FIRE_CONTROL+SOUND_HALTED+SOUND_RIGHT_SPEAKER
-		sta >SOUND_DATA_REG
-		lda #FIRE_CONTROL+SOUND_HALTED+SOUND_LEFT_SPEAKER
-		sta >SOUND_DATA_REG
+		_writeReg #SOUND_REG_CONTROL+FIRE_OSC_NUM,#FIRE_CONTROL+SOUND_HALTED+SOUND_RIGHT_SPEAKER
+		_writeReg #SOUND_REG_CONTROL+FIRE_OSC_NUM+1,#FIRE_CONTROL+SOUND_HALTED+SOUND_LEFT_SPEAKER
 		
-		lda #SOUND_REG_VOLUME+FIRE_OSC_NUM
-		sta >SOUND_ADDR_LOW
+		ldy #SOUND_REG_VOLUME+FIRE_OSC_NUM
+		lda tileRightVolume,x
+		jsr writeReg
+		ldy #SOUND_REG_VOLUME+FIRE_OSC_NUM+1
 		lda tileRightVolume,x
-		sta >SOUND_DATA_REG
 		eor #$ff
-		sta >SOUND_DATA_REG
+		jsr writeReg
 		
-		lda #SOUND_REG_CONTROL+FIRE_OSC_NUM
-		sta >SOUND_ADDR_LOW
-		lda #FIRE_CONTROL+SOUND_RIGHT_SPEAKER
-		sta >SOUND_DATA_REG
-		lda #FIRE_CONTROL+SOUND_LEFT_SPEAKER
-		sta >SOUND_DATA_REG
+		_writeReg #SOUND_REG_CONTROL+FIRE_OSC_NUM,#FIRE_CONTROL+SOUND_RIGHT_SPEAKER
+		_writeReg #SOUND_REG_CONTROL+FIRE_OSC_NUM+1,#FIRE_CONTROL+SOUND_LEFT_SPEAKER
 		
 		long m
 		rtl
@@ -1314,5 +1326,6 @@ fleaVolume			dc i2'0'
 segmentSoundIsPlaying	dc i2'1'
 spiderSoundIsPlaying	dc i2'1'
 scorpionSoundIsPlaying	dc i2'1'
+registerValue		dc i2'0'
 
         end

BuGS/global.macros

@@ -253,3 +253,18 @@ _incrementScore_noExtraMan&SYSCNT anop
 _incrementScore_no2000&SYSCNT anop
         sta scoreWithin20000,x
         mend
+
+; Wait for the DOC to be ready
+        macro
+        _docWait
+_docWait_&SYSCNT anop
+        lda >SOUND_CONTROL_REG
+        bmi _docWait_&SYSCNT
+        mend
+        
+        macro
+        _writeReg &reg,&value
+        ldy &reg
+        lda &value
+        jsr writeReg
+        mend

BuGS/make/launchEmulator

@@ -29,7 +29,7 @@ then
 fi
 
 # This magic ensures that clicking stop in Xcode results in the emulator terminating.
-if true
+if false
 then
     cd make
     sed -i "" "s:^s7d1 *=.*$:s7d1 = $BOOTIMAGE: