fixed bugs

simulator_SIC_XE/gui/qt/mainwindow.cpp

@@ -19,6 +19,7 @@
 #include <QFont>
 #include <QFileDialog>
 #include <QMessageBox>
+#include <QScrollBar>
 
 class Loader;
 
@@ -698,8 +699,19 @@ MainWindow::DisassembledInstruction MainWindow::disassembleAt(int address)
                 QString reg1Str = (r1 < 10) ? regNames[r1] : "?";
                 QString reg2Str = (r2 < 10) ? regNames[r2] : "?";
                 
+                // Check if this is a single-operand Format 2 instruction
+                QString mnem = result.mnemonic.toUpper();
+                if (mnem == "CLEAR" || mnem == "TIXR") {
+                    result.operand = reg1Str;
+                } else if (mnem == "SVC") {
+                    result.operand = QString::number(r1);
+                } else if (mnem == "SHIFTL" || mnem == "SHIFTR") {
+                    result.operand = QString("%1, %2").arg(reg1Str).arg(r2);
+                } else {
+                    // Two register operands (ADDR, SUBR, COMPR, etc.)
                     result.operand = QString("%1, %2").arg(reg1Str).arg(reg2Str);
                 }
+            }
             break;
         }
             
@@ -852,7 +864,13 @@ void MainWindow::updateDisassemblyDisplay()
     layout->addStretch();
     container->setLayout(layout);
     
+    // Save scroll position before updating
+    int scrollPos = ui->DisasemblyScrollArea->verticalScrollBar()->value();
+    
     ui->DisasemblyScrollArea->setWidget(container);
+    
+    // Restore scroll position after updating
+    ui->DisasemblyScrollArea->verticalScrollBar()->setValue(scrollPos);
 }
 
 void MainWindow::updateMemoryDisplay()
@@ -919,7 +937,11 @@ void MainWindow::updateMemoryDisplay()
     layout->addStretch();
     container->setLayout(layout);
     
+    int scrollPos = ui->MemoryScrollArea->verticalScrollBar()->value();
+    
     ui->MemoryScrollArea->setWidget(container);
+    
+    ui->MemoryScrollArea->verticalScrollBar()->setValue(scrollPos);
 }
 
 void MainWindow::loadObjectFile()

simulator_SIC_XE/include/file_device.h

@@ -17,6 +17,7 @@ private:
     std::fstream fileStream;
     std::string filename;
     bool fileCreated;
+    std::streampos readPosition;
 };
 
 #endif // FILE_DEVICE_H

simulator_SIC_XE/src/file_device.cpp

@@ -3,9 +3,8 @@
 #include <fstream>
 
 FileDevice::FileDevice(const std::string &filename)
-    : filename(filename), fileCreated(false)
+    : filename(filename), fileCreated(false), readPosition(0)
 {
-    // Don't create the file yet - wait until first write
 }
 
 FileDevice::~FileDevice()
@@ -18,9 +17,16 @@ FileDevice::~FileDevice()
 void FileDevice::ensureFileOpen()
 {
     if (!fileStream.is_open()) {
-        if (fileCreated) {
+        // Check if file exists
-            fileStream.open(filename, std::ios::in | std::ios::out);
+        std::ifstream checkFile(filename);
+        bool fileExists = checkFile.good();
+        checkFile.close();
+        
+        if (fileExists) {
+            fileStream.open(filename, std::ios::in | std::ios::out | std::ios::ate);
+            fileCreated = true;
         } else {
+            // Create new file
             std::ofstream create(filename);
             if (!create) {
                 throw std::runtime_error("Failed to create file: " + filename);
@@ -41,9 +47,11 @@ unsigned char FileDevice::read()
     unsigned char value = 0;
     ensureFileOpen();
     if (fileStream.is_open()) {
+        fileStream.seekg(readPosition);
         char ch;
         if (fileStream.get(ch)) {
             value = static_cast<unsigned char>(ch);
+            readPosition = fileStream.tellg();
         }
     }
     return value;
@@ -53,6 +61,7 @@ void FileDevice::write(unsigned char value)
 {
     ensureFileOpen();
     if (fileStream.is_open()) {
+        fileStream.seekp(0, std::ios::end);
         fileStream.put(static_cast<char>(value));
         fileStream.flush();
     }

simulator_SIC_XE/src/loader.cpp

@@ -1,8 +1,10 @@
 #include "loader.h"
 #include "file_reader.h"
+#include "string_reader.h"
 #include "machine.h"
 #include "constants.h"
 #include <algorithm>
+#include <cstdio>
 
 Loader::~Loader()
 {
@@ -82,20 +84,24 @@ Loader::TextRecord Loader::readTextRecord()
     if(FILE_CONTAINS_WHITE_SPACES) _file_reader->readByte();
 
     // Read length (1 byte, 2 hex digits)
-    int length = std::stoi(_file_reader->readString(2), nullptr, 16);
+    std::string lengthStr = _file_reader->readString(2);
-    if(FILE_CONTAINS_WHITE_SPACES) _file_reader->readByte();
+    int length = std::stoi(lengthStr, nullptr, 16);
     
+    // Read the rest of the line (data bytes with spaces)
+    std::string dataLine = _file_reader->readLine();
+    
+    // Remove all whitespace from the data line
+    dataLine.erase(std::remove_if(dataLine.begin(), dataLine.end(), ::isspace), dataLine.end());
+    
+    // Now use StringReader to parse the hex bytes
+    StringReader stringReader(dataLine);
     record.data.resize(length);
     
-    int index = 0;
-    string byteStr = _file_reader->readLine();
-    // Remove spaces, newlines, and other whitespace characters
-    byteStr.erase(std::remove_if(byteStr.begin(), byteStr.end(), ::isspace), byteStr.end());
-
     for (int i = 0; i < length; ++i) {
-        std::string byteHex = byteStr.substr(i * 2, 2);
+        std::string byteHex = stringReader.readString(2);
         record.data[i] = static_cast<uint8_t>(std::stoi(byteHex, nullptr, 16));
     }
+    
     return record;
 }
 

simulator_SIC_XE/src/machine.cpp

@@ -14,6 +14,17 @@ string prefix = "Machine error: ";
 
 Machine::Machine()
 {
+    // Initialize registers and memory to zero
+    A = B = X = L = S = T = PC = SW = 0;
+    F = 0.0;
+    for (int i = 0; i < MEMORY_SIZE; i++) {
+        memory[i] = 0;
+    }
+    for (int i = 0; i < VECTOR_REG_SIZE; i++) {
+        VA[i] = VS[i] = VT[i] = 0;
+    }
+    _stopped = false;
+    
     devices.resize(NUM_DEVICES);
     // device 0: standard input
     devices[0] = make_shared<InputDevice>(std::cin);