diff --git a/aica/aica_common.hpp b/aica/aica_common.hpp
index fb144b3..9e98845 100644
--- a/aica/aica_common.hpp
+++ b/aica/aica_common.hpp
@@ -263,11 +263,11 @@ struct aica_common {
 
   uint32_t SGC() const
   {
-    return (static_cast<uint32_t>((reg_2810 >> 14) & 0x1) << 0);
+    return (static_cast<uint32_t>((reg_2810 >> 13) & 0x3) << 0);
   }
   void SGC(const uint32_t v)
   {
-    reg_2810 = (((v >> 0) & 0x1) << 14) | (reg_2810 & 0xbfff);
+    reg_2810 = (((v >> 0) & 0x3) << 13) | (reg_2810 & 0x9fff);
   }
 
   uint32_t EG() const
@@ -714,7 +714,7 @@ namespace aica {
   }
   namespace lp_sgc_eg {
     constexpr uint32_t LP(const uint32_t reg) { return (static_cast<uint32_t>((reg >> 15) & 0x1) << 0); }
-    constexpr uint32_t SGC(const uint32_t reg) { return (static_cast<uint32_t>((reg >> 14) & 0x1) << 0); }
+    constexpr uint32_t SGC(const uint32_t reg) { return (static_cast<uint32_t>((reg >> 13) & 0x3) << 0); }
     constexpr uint32_t EG(const uint32_t reg) { return (static_cast<uint32_t>((reg >> 0) & 0x1fff) << 0); }
   }
   namespace ca {
diff --git a/regs/aica_common_data.csv b/regs/aica_common_data.csv
index fa9a54b..3d7eac8 100644
--- a/regs/aica_common_data.csv
+++ b/regs/aica_common_data.csv
@@ -17,7 +17,7 @@
 "MSLC",,"0x280c","13-8",,"w"
 "MOBUF",,"0x280c","7-0",,"w"
 "LP",,"0x2810","15",,"r"
-"SGC",,"0x2810","14",,"r"
+"SGC",,"0x2810","14-13",,"r"
 "EG",,"0x2810","12-0",,"r"
 "CA",,"0x2814","15-0",,"r"
 "DMEA","0","0x2880","15-9","22-16","w"
diff --git a/regs/aica_common_data.ods b/regs/aica_common_data.ods
index b024189..b2a734f 100644
Binary files a/regs/aica_common_data.ods and b/regs/aica_common_data.ods differ