From 56883335b5539578feb984d3676afc452824de8e Mon Sep 17 00:00:00 2001
From: Bobbi Webber-Manners <bobbi.manners@gmail.com>
Date: Fri, 25 Nov 2022 23:09:40 -0500
Subject: [PATCH] Ensoniq noise channel is now feature-complete.

---
 applecorn.po    | Bin 819200 -> 819200 bytes
 mainmem.audio.s |   3 +--
 mainmem.ensq.s  |  10 +++++++++-
 mame_applecorn  |   0
 4 files changed, 10 insertions(+), 3 deletions(-)
 mode change 100644 => 100755 mame_applecorn

diff --git a/applecorn.po b/applecorn.po
index 4f1b0e50051c2c158eb0e57872538d636c3a3bfc..13f6c6c39b45dc85024a7db82a47cd33e3076a83 100644
GIT binary patch
delta 538
zcmZo@FluNp+K|p7kn6=zscS99(D0Z+0mNu7XK62IVFY3(AZ7+)5T6x@*?^cGh&h0m
zb9*@p*R-9Cb=&#&am7ohK1}ymJIV6{ONLK#N`}w3bP$KxM?KYtDFecEOZAbOKIt0Q
zV#c`XX4kngfz*QQTniY3r#s%@60J{7UBIwXX%UM;bIPJ63pf<O{Dwu$K>oa!@uvj7
zCn#iqWEg-l2_Cni`r=X_FnkDnz<7cEB*O>hUbR$@6+7$FR;*-Dh)4yh$pG?FSFBWk
z@T#I#IzU)JTN>c318`RT0tmCg(L<Bv1Iq%Y2Brm!iyA-%X)>?asSGwfb;TkDphy+S
zo<$&sEOMxd0#OGRuz;uqVAoas%1D@+YRYgc3fVnXKpv8NekI(3JE`hd!VM9H#>8xi
z+_=<L2@Gp(4jBAS@KA`~9&?k+l8I4o`n20zMmlyGrv!ejv{=NhV3(1ga6WxyeJ|gU
zwJou|9kB`w`yJb36Fj0;C@^JIDM)23yTkQPJ0sy1Fo*=ZthiR~%*_Pqda*M%14sew
f28#1`No2CGn&AZm3U=G&PjR=hY~OH>J76OKV6D;p

delta 530
zcmZo@FluNp+K|p7km$uwsjDZ-(D0Z+0mNu7XK62IVFY3(AZ7+)5T6x@*?^cGh&h0m
zb9*@p*R-9CMceuIam7ohUQPE{JIV6{ONLK#N`}v?bP$KxM>^H#8<c64>ccmE(lxHd
zj6u`Qu5)DqsRh@$7BIR`cf7$RS|6FZfMKQ5A{K?_ltoJxa43NJ4U3q8{CO|qPYHZa
zP{;tuFaTu|JZ?qx1*JY<_~7QTVrNm>ij@osKB+*73?MIc#YzPTuPSP#1B3-Mx&h8Q
z0B0?Luo@gaH0xPDuq<F|U|PVqr~zb<Ci9A&5~(25Q&%if0E$$B>{$e|eUU>|6o@*o
zfCWS?06VGbS4P6rRMT5g$j+$(@{pYKE8!O0MOD8NZYVS+W=rG-rLIa~Sj%B^z~Fa+
zheGi7jGJ7ROpHp?7v1JEvM|axCGcyd#UgeEql^TF!|5yQd-;y6ZHeveh*e<N@7Nxj
z;1RV#;ahr@0$)Z(!YyEk2zFU<t=hTl4%a*R#7v;B7dsO(fE3Vfpd@dXL?-*H8D2o3
XV6<KP6n87jWC13g?HkT<2W$iY`i9L;

diff --git a/mainmem.audio.s b/mainmem.audio.s
index e0e0cf0..c5c88b6 100644
--- a/mainmem.audio.s
+++ b/mainmem.audio.s
@@ -732,7 +732,6 @@ ADSRPHASE   STX   OSCNUM
 :S1         TYA                             ; Change/step -> A
             CLC
             ADC   CURRAMP,X                 ; Add change to current amp
-*            BCS   :CLAMP                    ; If overflow, clamp to target
             CMP   :TARGET                   ; Compare with target
             BCS   :CLAMP                    ; If target < sum, clamp to target
             BRA   :UPDATE                   
@@ -743,7 +742,7 @@ ADSRPHASE   STX   OSCNUM
 :S2         TYA                             ; Change/step -> A
             CLC
             ADC   CURRAMP,X                 ; Add change to current amp
-            BCS   :CLAMP                    ; If overflow, clamp to target
+            BCS   :CLAMP                    ; If overflow (-ve), clamp to target
             CMP   :TARGET                   ; Compare with target
             BCC   :CLAMP                    ; If target >= sum, clamp to target
             BRA   :UPDATE                   
diff --git a/mainmem.ensq.s b/mainmem.ensq.s
index 8c2968c..806d757 100644
--- a/mainmem.ensq.s
+++ b/mainmem.ensq.s
@@ -2,6 +2,7 @@
 * (c) Bobbi 2022 GPLv3
 *
 * Ensoniq DOC Driver for Apple IIGS.
+* Simulates Hitachi SN76489 sound generator chip found in BBC Micro.
 *
 
 * Ensoniq control registers
@@ -145,7 +146,13 @@ ENSQNOTE    PHA
             CPX   #$00
             BEQ   :NOISE                    ; Oscillator 0 is noise channel
 
-            PHA                             ; Stash orig freq
+            CPX   #$01                      ; Oscillator 1 controls noise freq
+            BNE   :S0                       ; Not 1? Skip
+            CMP   #$00                      ; If frequency is zero ..
+            BEQ   :S0                       ; .. skip
+            STA   :CH1NOTE                  ; Store frequency for noise gen
+
+:S0         PHA                             ; Stash orig freq
             TAY
             LDA   EFREQLOW,Y
             TAY                             ; Frequency value LS byte
@@ -232,6 +239,7 @@ ENSQNOTE    PHA
 :NOISENOTE  DB    149                       ; BBC Micro note P=0 or 4
             DB    101                       ; BBC Micro note P=1 or 5
             DB    53                        ; BBC Micro note P=2 or 6
+:CH1NOTE    DB    00                        ; Note on channel 1
 
 
 * Adjust frequency of note already playing
diff --git a/mame_applecorn b/mame_applecorn
old mode 100644
new mode 100755