Fixed the Noraut Poker discrete sound system. Rerouted the PPI-1 lines PC5 & PC6. Now the scheme has more sense from a hardware point of view. All sounds are now accurate based on real references. Also corrected the original diagram.

src/mame/audio/norautp.c

@@ -15,8 +15,8 @@
 #define NORAUTP_R2		RES_K(2.2)
 
 /* Parts List - Capacitors */
-#define NORAUTP_C1		CAP_U(.022)
-#define NORAUTP_C2		CAP_U(.01)
+#define NORAUTP_C1		CAP_U(.009)		/* The real value is .01, but using .009 the tone for this line is accurate */ 
+#define NORAUTP_C2		CAP_U(.022)
 #define NORAUTP_C3		CAP_U(.047)
 #define NORAUTP_C4		CAP_U(.01)
 

src/mame/drivers/norautp.c

@@ -17,6 +17,10 @@
    * Noraut Poker (bootleg),       198?,  Unknown.
 
 
+  Special thanks to Alan Griffin, that kindly helped providing good references
+  that allowed me to improve the system emulation.
+
+
 *******************************************************************************
 
 
@@ -250,8 +254,8 @@
   R2 = 2.2 K ; Tolerance +/- 5%
   R3 = 1 K   ; Tolerance +/- 5%
 
-  C1 = 223J = 22000 pF  =  22 nF = 0.022 uF ; Tolerance +/- 5%
-  C2 = 103J = 10000 pF  =  10 nF = 0.01 uF  ; Tolerance +/- 5%
+  C1 = 103J = 10000 pF  =  10 nF = 0.01 uF  ; Tolerance +/- 5%
+  C2 = 223J = 22000 pF  =  22 nF = 0.022 uF ; Tolerance +/- 5%
   C3 = 473J = 47000 pF  =  47 nF = 0.047 uF ; Tolerance +/- 5%
   C4 = 103J = 10000 pF  =  10 nF = 0.01 uF  ; Tolerance +/- 5%
 
@@ -514,6 +518,12 @@
     It has 2 jumpers that cut the a14 and a15 addressing lines.
 
 
+  [2009-09-09]
+
+  - Added accurate discrete sound system emulation.
+  - Fixed the discrete sound system diagram, based on real sound references.
+
+
   TODO:
 
   - Analize PPI-2 at 0xc0-0xc3. OBF handshake line (PC7) doesn't seems to work properly.