From f8df4908fe6986e691ea96b4b07ffbff349ccce0 Mon Sep 17 00:00:00 2001
From: alekseiplusplus <alekseijeaves@protonmail.com>
Date: Thu, 7 Dec 2023 17:34:18 +1100
Subject: changed shift ins.s and now log CPU state

---
 src/cpu/instructions.c | 114 +++++++++++++++++++++----------------------------
 1 file changed, 49 insertions(+), 65 deletions(-)

(limited to 'src/cpu/instructions.c')

diff --git a/src/cpu/instructions.c b/src/cpu/instructions.c
index abe6365..2b034c4 100644
--- a/src/cpu/instructions.c
+++ b/src/cpu/instructions.c
@@ -65,7 +65,7 @@ void fSBC(Addressing addr){
         
 	SetFlagV(buffer, acc);
 
-	SetFlag(flag_C, (buffer > acc) ? 1 : 0);
+	SetFlag(flag_C, (buffer > acc) ? 0 : 1);
 
 	acc = buffer;
 	
@@ -190,81 +190,65 @@ void fCPY(Addressing addr){
 }
 
 void fBIT(Addressing addr){
-	SetFlag(flag_N, ((idata.value & flag_N) != 0) ? 1 : 0);
-	SetFlag(flag_V, ((idata.value & flag_V) != 0) ? 1 : 0);
-	SetFlag(flag_Z, ((idata.value & acc)    == 0) ? 1 : 0);
+	SetFlag(flag_N, ((idata.value & flag_N) != 0));
+	SetFlag(flag_V, ((idata.value & flag_V) != 0));
+	SetFlag(flag_Z, ((idata.value &    acc) == 0));
 }
 
 // Shift and Rotate Instructions
 
 void fASL(Addressing addr){
-  if (addr == eAccumulator) {
-    SetFlag(flag_C, (acc & 0x80));
-    acc = (idata.value << 1) & 0xFE;
-    SetFlagN(acc);
-    SetFlagZ(acc);
-  }
-  else {
-    SetFlag(flag_C, (idata.value & 0x80));
-    byte m = ((idata.value << 1) & 0xFE);
-    SetMemory(idata.add, m);
-    SetFlagN(m);
-    SetFlagZ(m);
-  }
-}
-
-void fLSR(Addressing addr){
-  if (addr == eAccumulator) {
-    SetFlag(flag_C, (acc & 0x01));
-    acc = (idata.value >> 1) & 0x7F;
-    SetFlagN(acc);
-    SetFlagZ(acc);
-  }
-  else {
-    SetFlag(flag_C, (idata.value & 0x01));
-    byte m = ((idata.value >> 1) & 0x7F);
-    SetMemory(idata.add, m);
-    SetFlagN(m);
-    SetFlagZ(m);
-  }
+	byte m = (addr == eAccumulator) ? acc : idata.value;
+	
+	SetFlag(flag_C, (m & 0b10000000));
+	m = (m << 1) & 0b11111110;
+	SetFlagN(m);
+	SetFlagZ(m);
+	
+	(addr == eAccumulator)
+	?	acc = m
+	:	SetMemory(idata.add, m);
+}
+
+void fLSR(Addressing addr) {
+	byte m = (addr == eAccumulator) ? acc : idata.value;
+	
+	SetFlag(flag_C, (m & 0b00000001));
+	m = (m >> 1) & 0b01111111;
+	SetFlagN(m);
+	SetFlagZ(m);
+	
+	(addr == eAccumulator)
+	?	acc = m
+	:	SetMemory(idata.add, m);
 }
 
 void fROL(Addressing addr){
-  if (addr == eAccumulator) {
-    SetFlag(flag_C, (idata.value & 0x80));
-    acc = (idata.value << 1) & 0xFE;
-    acc |= ((getFlag(flag_C) != 0) ? 0x01 : 0x00);
-    SetFlagN(acc);
-    SetFlagZ(acc);
-  }
-  else {
-    SetFlag(flag_C, (idata.value & 0x80));
-    byte m =
-      (((idata.value << 1) & 0xFE)
-      | ((getFlag(flag_C) != 0) ? 0x01 : 0x00));
-    SetMemory(idata.add, m);
-    SetFlagN(m);
-    SetFlagZ(m);
-  }
+	byte m = (addr == eAccumulator) ? acc : idata.value;
+	
+	SetFlag(flag_C, (m & 0b10000000));
+	m = (m << 1) & 0b11111110;
+	m |= (getFlag(flag_C)) ? 0b00000001 : 0;
+	SetFlagN(m);
+	SetFlagZ(m);
+	
+	(addr == eAccumulator)
+	?	acc = m
+	:	SetMemory(idata.add, m);
 }
 
 void fROR(Addressing addr){
-  if (addr == eAccumulator) {
-    SetFlag(flag_C, (idata.value & 0x01));
-    acc = (idata.value >> 1) & 0x7F;
-    acc |= ((getFlag(flag_C) != 0) ? 0x80 : 0x00);
-    SetFlagN(acc);
-    SetFlagZ(acc);
-  }
-  else {
-    SetFlag(flag_C, (idata.value & 0x01));
-    byte m =
-      (((idata.value >> 1) & 0x7F)
-      | ((getFlag(flag_C) != 0) ? 0x80 : 0x00));
-    SetMemory(idata.add, m);
-    SetFlagN(m);
-    SetFlagZ(m);
-  }
+	byte m = (addr == eAccumulator) ? acc : idata.value;
+	
+	SetFlag(flag_C, (m & 0b00000001));
+	m = (m >> 1) & 0b01111111;
+	m |= (getFlag(flag_C)) ? 0b10000000 : 0;
+	SetFlagN(m);
+	SetFlagZ(m);
+	
+	(addr == eAccumulator)
+	?	acc = m
+	:	SetMemory(idata.add, m);
 }
 
 // Transfer Instructions
-- 
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