diff --git a/A2Mac/ViewController.swift b/A2Mac/ViewController.swift
index 4458b97..712f611 100644
--- a/A2Mac/ViewController.swift
+++ b/A2Mac/ViewController.swift
@@ -13,9 +13,13 @@ class ViewController: NSViewController {
     @IBOutlet weak var display: NSTextFieldCell!
     
     func check() {
-        let ram = UnsafeRawBufferPointer(start: &RAM+0x400, count: 0x400)
-        let string = String(bytes: ram, encoding: .utf8)
-        print(string)
+        let textBufferPointer = UnsafeRawBufferPointer(start: &RAM+0x400, count: 0x400)
+//        let string = String(bytes: ram, encoding: .utf8)
+//        print(string)
+        
+        for (index, byte) in textBufferPointer.enumerated() {
+            print("byte \(index): \(byte)")
+        }
     }
     
     
@@ -63,9 +67,9 @@ class ViewController: NSViewController {
 //        }
 
 
-        DispatchQueue.main.asyncAfter(deadline: .now() + 5.0, execute: {
-            self.check()
-        })
+//        DispatchQueue.main.asyncAfter(deadline: .now() + 5.0, execute: {
+//            self.check()
+//        })
         
     }
 
diff --git a/A2Mac/common.h b/A2Mac/common.h
index 93600ab..cf55131 100644
--- a/A2Mac/common.h
+++ b/A2Mac/common.h
@@ -65,7 +65,7 @@ static inline void set_flags_NVZ( uint8_t test ) {
 
 static inline void set_flags_NZC( int test ) {
     set_flags_NZ(test);
-    m6502.flags.C = (unsigned)test  > 0xFF;
+    m6502.flags.C = test >= 0;
 }
 
 static inline void set_flags_NZCV( int test ) {
diff --git a/A2Mac/instructions/6502_instr_arithmetic.h b/A2Mac/instructions/6502_instr_arithmetic.h
index 1990d78..6e63cb3 100644
--- a/A2Mac/instructions/6502_instr_arithmetic.h
+++ b/A2Mac/instructions/6502_instr_arithmetic.h
@@ -53,10 +53,7 @@ static inline void ADC( uint8_t imm ) {
  (indirect),Y  SBC (oper),Y  F1    2     5*
 **/
 static inline void SBC( uint8_t imm ) {
-    int tmp = (int)m6502.A - imm - m6502.flags.C;
-    dbgPrintf("SBC A:%02X - i:%02X - C:%u = %02X", m6502.A, imm, m6502.flags.C, tmp);
-    m6502.A = (uint8_t)tmp;
-    set_flags_NZCV( tmp );
+    ADC( ~imm );
 }
 
 #endif // __6502_INSTR_ARITHMETIC_H__
diff --git a/A2Mac/instructions/6502_instr_load_store.h b/A2Mac/instructions/6502_instr_load_store.h
index b1a1393..d325a54 100644
--- a/A2Mac/instructions/6502_instr_load_store.h
+++ b/A2Mac/instructions/6502_instr_load_store.h
@@ -93,7 +93,6 @@ static inline void STR( uint8_t * dst, uint8_t imm ) {
     *dst = imm;
 
 //    uint16_t v = dst - RAM;
-    
 //    if ( ( v >= 0x400 ) && ( v < 0x800 ) ) {
 //        char c = charConv[imm];
 //        if (( imm > ' ' ) && ( c < 0x7F ))