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Fixed slightly wrong high-pass cutoff for A1200

--- a/src/pt2_header.h

+++ b/src/pt2_header.h

@@ -14,7 +14,7 @@

 #include "pt2_unicode.h"

 #include "pt2_palette.h"

-#define PROG_VER_STR "1.55"

+#define PROG_VER_STR "1.56"

 #ifdef _WIN32

 #define DIR_DELIMITER '\\'

--- a/src/pt2_paula.c

+++ b/src/pt2_paula.c

@@ -70,8 +70,6 @@

 	** Low Hz = 4420.97~ = 1 / (2pi * 360 * 0.0000001)

 	**

 	** Under spice simulation the circuit yields -3dB = 4400Hz.

-	** In the Amiga 1200, the low-pass cutoff is ~34kHz, so the

-	** static low-pass filter is disabled in the mixer in A1200 mode.

 	**

 	** Next comes a bog-standard Sallen-Key filter ("LED") with:

 	** R1 = 10K ohm

@@ -78,7 +76,7 @@

 	** R2 = 10K ohm

 	** C1 = 6800pF

 	** C2 = 3900pF

-	** Q ~= 1/sqrt(2)

+	**  Q = 0.660 (8bitbubsy: edited with correct nominal)

 	**

 	** This filter is optionally bypassed by an MPF-102 JFET chip when

 	** the LED filter is turned off.

@@ -107,7 +105,7 @@

 	** Correct values for A1200, all revs (A1200_R2.pdf):

 	** - 1-pole RC 6dB/oct low-pass: R=680 ohm, C=6800pF

 	** - Sallen-key low-pass ("LED"): R1/R2=10k ohm, C1=6800pF, C2=3900pF (same as A500)

-	** - 1-pole RC 6dB/oct high-pass: R=1390 ohm (1000+390), C=22uF

+	** - 1-pole RC 6dB/oct high-pass: R=1360 ohm (1000+360), C=22uF

 	*/

 	double R, C, R1, R2, C1, C2, cutoff, qfactor;

@@ -135,9 +133,9 @@

 		useLowpassFilter = false;

 		// A1200 1-pole (6dB/oct) static RC high-pass filter:

-		R = 1390.0; // R324 (1K ohm resistor) + R325 (390 ohm resistor)

+		R = 1360.0; // R324 (1K ohm resistor) + R325 (360 ohm resistor)

 		C = 2.2e-5; // C334 (22uF capacitor)

-		cutoff = 1.0 / (PT2_TWO_PI * R * C); // ~5.205Hz

+		cutoff = 1.0 / (PT2_TWO_PI * R * C); // ~5.319Hz

 		calcRCFilterCoeffs(dPaulaOutputFreq, cutoff, &filterHi);

 	}