From 94ed39f5e28520ba968a604c7eeabf2be0ca35d7 Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Sun, 27 Aug 2017 18:02:43 +0200
Subject: JTACS: Implementation of the Japanese variant of TACS

---
 src/amps/amps.c | 20 ++++++++++++++++----
 src/amps/main.c |  1 +
 src/amps/main.h |  1 +
 3 files changed, 18 insertions(+), 4 deletions(-)

(limited to 'src/amps')

diff --git a/src/amps/amps.c b/src/amps/amps.c
index 2150ecb..74abbc4 100644
--- a/src/amps/amps.c
+++ b/src/amps/amps.c
@@ -83,16 +83,28 @@ double amps_channel2freq(int channel, int uplink)
 			channel -= 1023;
 
 		freq = 870.030 + (channel - 1) * 0.030;
-	} else {
+
+		if (uplink)
+			freq -= 45.000;
+	} else if (!jtacs) {
 		/* 600 channels */
 		if (channel < 1 || channel > 600)
 			return 0;
 
 		freq = 935.0125 + (channel - 1) * 0.025;
-	}
 
-	if (uplink)
-		freq -= 45.000;
+		if (uplink)
+			freq -= 45.000;
+	} else {
+		/* 799 channels */
+		if (channel < 1 || channel > 799)
+			return 0;
+
+		freq = 860.0125 + (channel - 1) * 0.025;
+
+		if (uplink)
+			freq += 55.000;
+	}
 
 	return freq * 1e6;
 }
diff --git a/src/amps/main.c b/src/amps/main.c
index ce0e065..4c8e445 100644
--- a/src/amps/main.c
+++ b/src/amps/main.c
@@ -6,6 +6,7 @@
 #include "congestion.h"
 
 const int tacs = 0;
+const int jtacs = 0;
 
 int main(int argc, char *argv[])
 {
diff --git a/src/amps/main.h b/src/amps/main.h
index 323b94a..23acd6a 100644
--- a/src/amps/main.h
+++ b/src/amps/main.h
@@ -1,5 +1,6 @@
 
 extern const int tacs;
+extern const int jtacs;
 
 int main_amps_tacs(int argc, char *argv[]);
 
-- 
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