diff --git a/CDChecksums.cs b/CDChecksums.cs
index 2ee8206..29bf911 100644
--- a/CDChecksums.cs
+++ b/CDChecksums.cs
@@ -32,6 +32,7 @@
 // ****************************************************************************/
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using DiscImageChef.Console;
 
@@ -292,8 +293,6 @@ namespace DiscImageChef.Checksums
                                               channel[0x00C], channel[0x00D], channel[0x00E], calculatedEdc, storedEdc);
                     return false;
                 }
-
-                return true;
             }
 
             DicConsole.DebugWriteLine("CD checksums", "Unknown mode {0} sector at address: {1:X2}:{2:X2}:{3:X2}",
@@ -301,7 +300,7 @@ namespace DiscImageChef.Checksums
             return null;
         }
 
-        static uint ComputeEdc(uint edc, byte[] src, int size)
+        static uint ComputeEdc(uint edc, IReadOnlyList<byte> src, int size)
         {
             int pos                     = 0;
             for(; size > 0; size--) edc = (edc >> 8) ^ edcTable[(edc ^ src[pos++]) & 0xFF];
@@ -309,7 +308,7 @@ namespace DiscImageChef.Checksums
             return edc;
         }
 
-        static bool? CheckCdSectorSubChannel(byte[] subchannel)
+        static bool? CheckCdSectorSubChannel(IReadOnlyList<byte> subchannel)
         {
             bool?  status       = true;
             byte[] qSubChannel  = new byte[12];
diff --git a/ReedSolomon.cs b/ReedSolomon.cs
index d80ac8f..ca53d86 100644
--- a/ReedSolomon.cs
+++ b/ReedSolomon.cs
@@ -231,9 +231,9 @@ namespace DiscImageChef.Checksums
         */
         void generate_gf()
         {
-            int i, mask;
+            int i;
 
-            mask = 1;
+            int mask = 1;
             alpha_to[mm] = 0;
             for(i = 0; i < mm; i++)
             {
@@ -372,8 +372,7 @@ namespace DiscImageChef.Checksums
             if(!initialized) throw new UnauthorizedAccessException("Trying to calculate RS without initializing!");
 
             erasPos = new int[nn - kk];
-            int degLambda, el, degOmega;
-            int i, j, r;
+            int i, j;
             int q, tmp;
             int[] recd = new int[nn];
             int[] lambda = new int[nn - kk + 1]; /* Err+Eras Locator poly */
@@ -384,7 +383,7 @@ namespace DiscImageChef.Checksums
             int[] root = new int[nn - kk];
             int[] reg = new int[nn - kk + 1];
             int[] loc = new int[nn - kk];
-            int synError, count;
+            int count;
 
             /* data[] is in polynomial form, copy and convert to index form */
             for(i = nn - 1; i >= 0; i--)
@@ -396,7 +395,7 @@ namespace DiscImageChef.Checksums
             /* first form the syndromes; i.e., evaluate recd(x) at roots of g(x)
              * namely @**(B0+i), i = 0, ... ,(NN-KK-1)
              */
-            synError = 0;
+            int synError = 0;
             for(i = 1; i <= nn - kk; i++)
             {
                 tmp = 0;
@@ -471,8 +470,8 @@ namespace DiscImageChef.Checksums
              * Begin Berlekamp-Massey algorithm to determine error+erasure
              * locator polynomial
              */
-            r = noEras;
-            el = noEras;
+            int r = noEras;
+            int el = noEras;
             while(++r <= nn - kk)
             {
                 /* r is the step number */
@@ -518,7 +517,7 @@ namespace DiscImageChef.Checksums
             }
 
             /* Convert lambda to index form and compute deg(lambda(x)) */
-            degLambda = 0;
+            int degLambda = 0;
             for(i = 0; i < nn - kk + 1; i++)
             {
                 lambda[i] = index_of[lambda[i]];
@@ -561,7 +560,7 @@ namespace DiscImageChef.Checksums
              * Compute err+eras evaluator poly omega(x) = s(x)*lambda(x) (modulo
              * x**(NN-KK)). in index form. Also find deg(omega).
              */
-            degOmega = 0;
+            int degOmega = 0;
             for(i = 0; i < nn - kk; i++)
             {
                 tmp = 0;
diff --git a/SpamSumContext.cs b/SpamSumContext.cs
index b36a137..2ea280b 100644
--- a/SpamSumContext.cs
+++ b/SpamSumContext.cs
@@ -177,15 +177,13 @@ namespace DiscImageChef.Checksums
 
         void fuzzy_try_fork_blockhash()
         {
-            uint obh, nbh;
-
             if(self.Bhend >= NUM_BLOCKHASHES) return;
 
             if(self.Bhend == 0) // assert
                 throw new Exception("Assertion failed");
 
-            obh                     = self.Bhend - 1;
-            nbh                     = self.Bhend;
+            uint obh = self.Bhend - 1;
+            uint nbh = self.Bhend;
             self.Bh[nbh].H          = self.Bh[obh].H;
             self.Bh[nbh].Halfh      = self.Bh[obh].Halfh;
             self.Bh[nbh].Digest[0]  = 0;
@@ -213,13 +211,12 @@ namespace DiscImageChef.Checksums
 
         void fuzzy_engine_step(byte c)
         {
-            ulong h;
             uint  i;
             /* At each character we update the rolling hash and the normal hashes.
              * When the rolling hash hits a reset value then we emit a normal hash
              * as a element of the signature and reset the normal hash. */
             roll_hash(c);
-            h = roll_sum();
+            ulong h = roll_sum();
 
             for(i = self.Bhstart; i < self.Bhend; ++i)
             {
@@ -266,14 +263,13 @@ namespace DiscImageChef.Checksums
             StringBuilder sb = new StringBuilder();
             uint          bi = self.Bhstart;
             uint          h  = roll_sum();
-            int           i, resultOff;
             int           remain = (int)(FUZZY_MAX_RESULT - 1); /* Exclude terminating '\0'. */
             result               = new byte[FUZZY_MAX_RESULT];
             /* Verify that our elimination was not overeager. */
             if(!(bi == 0 || (ulong)SSDEEP_BS(bi) / 2 * SPAMSUM_LENGTH < self.TotalSize))
                 throw new Exception("Assertion failed");
 
-            resultOff = 0;
+            int resultOff = 0;
 
             /* Initial blocksize guess. */
             while((ulong)SSDEEP_BS(bi) * SPAMSUM_LENGTH < self.TotalSize)
@@ -289,7 +285,7 @@ namespace DiscImageChef.Checksums
             if(bi > 0 && self.Bh[bi].Dlen < SPAMSUM_LENGTH / 2) throw new Exception("Assertion failed");
 
             sb.AppendFormat("{0}:", SSDEEP_BS(bi));
-            i = Encoding.ASCII.GetBytes(sb.ToString()).Length;
+            int i = Encoding.ASCII.GetBytes(sb.ToString()).Length;
             if(i <= 0)
                 /* Maybe snprintf has set errno here? */ throw new OverflowException("The input exceeds data types.");
             if(i >= remain) throw new Exception("Assertion failed");