ADMOPSLA and ADMCHART are happier

j3270/src/main/java/org/pubvm/j3270/ui/TerminalPanel.java

@@ -180,6 +180,22 @@ public class TerminalPanel extends JPanel {
                 }
             }
 
+            @Override
+            public void mouseMoved(MouseEvent e) {
+                if (client != null && client.getGocaDecoder() != null && client.getGocaDecoder().isGraphicsCursorActive() && client.getGraphicsPlane() != null) {
+                    int ox = getRenderOffsetX();
+                    int oy = getRenderOffsetY();
+                    ScreenBuffer sb = client.getScreenBuffer();
+                    int gridW = sb.getDisplayCols() * cellWidth;
+                    int gridH = sb.getDisplayRows() * cellHeight;
+                    int gWidth = client.getGraphicsPlane().getCanvasWidth();
+                    int gHeight = client.getGraphicsPlane().getCanvasHeight();
+                    int px = (gridW > 0 && gWidth > 0) ? (int) Math.round((double) (e.getX() - ox) * gWidth / gridW) : (e.getX() - ox);
+                    int py = (gridH > 0 && gHeight > 0) ? (int) Math.round((double) (e.getY() - oy) * gHeight / gridH) : (e.getY() - oy);
+                    client.getGocaDecoder().setGraphicCursorFromPixel(px, py);
+                }
+            }
+
             @Override
             public void mouseReleased(MouseEvent e) {
                 if (isDragging) {
@@ -188,8 +204,35 @@ public class TerminalPanel extends JPanel {
                     if (selectionStartRow == selectionEndRow && selectionStartCol == selectionEndCol) {
                         if (client != null && client.getConnectionState().isFullSession()) {
                             ScreenBuffer sb = client.getScreenBuffer();
-                            sb.setCursorAddress(selectionStartRow * sb.getCols() + selectionStartCol);
+                            int newAddr = selectionStartRow * sb.getCols() + selectionStartCol;
+                            sb.setCursorAddress(newAddr);
                             clearSelection();
+                            
+                            if (client.getGocaDecoder() != null && client.getGraphicsPlane() != null) {
+                                int ox = getRenderOffsetX();
+                                int oy = getRenderOffsetY();
+                                int gridW = sb.getDisplayCols() * cellWidth;
+                                int gridH = sb.getDisplayRows() * cellHeight;
+                                int gWidth = client.getGraphicsPlane().getCanvasWidth();
+                                int gHeight = client.getGraphicsPlane().getCanvasHeight();
+                                int px = (gridW > 0 && gWidth > 0) ? (int) Math.round((double) (e.getX() - ox) * gWidth / gridW) : (e.getX() - ox);
+                                int py = (gridH > 0 && gHeight > 0) ? (int) Math.round((double) (e.getY() - oy) * gHeight / gridH) : (e.getY() - oy);
+                                client.getGocaDecoder().setGraphicCursorFromPixel(px, py);
+                                
+                                if (client.getGocaDecoder().isGraphicsCursorActive()) {
+                                    // Light-pen / Graphic cursor touch event (matches IBM Host On-Demand PS3179G)
+                                    int button = javax.swing.SwingUtilities.isRightMouseButton(e) ? 2 : 1;
+                                    client.getInputProcessor().sendGraphicMouseAid(
+                                        org.lib3270j.protocol.DS3270Constants.AID_ENTER,
+                                        button,
+                                        e.isShiftDown(),
+                                        e.isControlDown()
+                                    );
+                                    refreshScreen();
+                                    return;
+                                }
+                            }
+                            
                             refreshScreen();
                             return;
                         }
@@ -849,6 +892,20 @@ public class TerminalPanel extends JPanel {
         int cols = sb.getDisplayCols();
         boolean isColorModel = client.getConfig().getModel().isColor();
 
+        // Draw Vector Graphics Plane under text if present
+        if (client.getGraphicsPlane() != null && client.getGraphicsPlane().hasContent()) {
+            int gridW = cols * cellWidth;
+            int gridH = rows * cellHeight;
+            int gWidth = client.getGraphicsPlane().getCanvasWidth();
+            int gHeight = client.getGraphicsPlane().getCanvasHeight();
+            int[] rgb = client.getGraphicsPlane().getRgbBuffer();
+            if (rgb != null && gWidth > 0 && gHeight > 0) {
+                java.awt.image.BufferedImage img = new java.awt.image.BufferedImage(gWidth, gHeight, java.awt.image.BufferedImage.TYPE_INT_ARGB);
+                img.setRGB(0, 0, gWidth, gHeight, rgb, 0, gWidth);
+                g2.drawImage(img, ox, oy, gridW, gridH, null);
+            }
+        }
+
         // Track current field attribute for monochrome color decisions
         byte currentFA = 0;
         ExtendedAttribute currentFieldEa = null;
@@ -940,7 +997,8 @@ public class TerminalPanel extends JPanel {
                 if (cs >= 0x40 && client.getProgramSymbolManager() != null) {
                     org.lib3270j.graphics.ProgramSymbolSet.SymbolSlot slot = client.getProgramSymbolManager().getSymbol(cs, ea.ec & 0xFF);
                     if (slot != null) {
-                        java.awt.image.BufferedImage img = slot.getScaledImage(cellWidth, cellHeight, fgColor.getRGB(), bgColor.getRGB());
+                        int symBg = (!bgColor.equals(this.bgColor) || reverse) ? bgColor.getRGB() : 0;
+                        java.awt.image.BufferedImage img = slot.getScaledImage(cellWidth, cellHeight, fgColor.getRGB(), symBg);
                         if (img != null) {
                             g2.drawImage(img, x, y, null);
                             drawnAsPs = true;
@@ -977,20 +1035,22 @@ public class TerminalPanel extends JPanel {
             }
         }
 
-        // Draw Vector Graphics Plane overlay if present
+        // Draw Graphic Cursor (Light-Pen / interactive graphics pointer) if active
-        if (client.getGraphicsPlane() != null && client.getGraphicsPlane().hasContent()) {
+        if (client.getGocaDecoder() != null && client.getGocaDecoder().isGraphicsCursorActive() && client.getGraphicsPlane() != null) {
-            int gridW = cols * cellWidth;
+            int gocaX = client.getGocaDecoder().getGraphicCursorX();
-            int gridH = rows * cellHeight;
+            int gocaY = client.getGocaDecoder().getGraphicCursorY();
-            client.getGraphicsPlane().resize(gridW, gridH);
+            int px = ox + client.getGraphicsPlane().mapX(gocaX);
-            int[] rgb = client.getGraphicsPlane().getRgbBuffer();
+            int py = oy + client.getGraphicsPlane().mapY(gocaY);
-            if (rgb != null) {
+
-                java.awt.image.BufferedImage img = new java.awt.image.BufferedImage(gridW, gridH, java.awt.image.BufferedImage.TYPE_INT_ARGB);
+            g2.setColor(Color.WHITE);
-                img.setRGB(0, 0, gridW, gridH, rgb, 0, gridW);
+            g2.setXORMode(Color.BLACK);
-                g2.drawImage(img, ox, oy, gridW, gridH, null);
+            // Draw a crosshair cursor for the light-pen / graphic cursor
-            }
+            g2.drawLine(px - 6, py, px + 6, py);
+            g2.drawLine(px, py - 6, px, py + 6);
+            g2.setPaintMode();
         }
 
-        // Draw cursor
+        // Draw 3270 text cursor
         if (cursorVisible && client.getConnectionState().isFullSession()) {
             int curAddr = sb.getDisplayCursorAddress();
             int curRow = curAddr / cols;

lib3270j/src/main/java/org/lib3270j/DiagnosticClient.java

@@ -26,7 +26,7 @@ public class DiagnosticClient {
         String host = args.length >= 1 ? args[0] : "192.168.0.30";
         int port = args.length >= 2 ? Integer.parseInt(args[1]) : 3270;
 
-        ConnectionConfig config = new ConnectionConfig(host, port, TerminalModel.IBM_3279_2);
+        ConnectionConfig config = new ConnectionConfig(host, port, TerminalModel.IBM_3279_4);
         client = new Telnet3270Client(config);
 
         client.addConnectionListener(new ConnectionListener() {

lib3270j/src/main/java/org/lib3270j/Telnet3270Client.java

@@ -54,6 +54,7 @@ public class Telnet3270Client {
         dsProcessor.setOutputSender(fsm::send3270Data);
         dsProcessor.setInputProcessor(inputProcessor);
         inputProcessor.setGraphicsPlane(dsProcessor.getGraphicsPlane());
+        inputProcessor.setGocaDecoder(dsProcessor.getGocaDecoder());
     }
 
     /**

lib3270j/src/main/java/org/lib3270j/datastream/DataStreamProcessor.java

@@ -89,6 +89,10 @@ public class DataStreamProcessor {
         this.inputProcessor = inputProcessor;
     }
 
+    public org.lib3270j.input.InputProcessor getInputProcessor() {
+        return inputProcessor;
+    }
+
     public void addScreenUpdateListener(ScreenUpdateListener l) {
         screenListeners.add(l);
     }
@@ -175,6 +179,7 @@ public class DataStreamProcessor {
                 case CMD_WSF:
                 case SNA_CMD_WSF:
                     processWriteStructuredField(data, offset, length);
+                    keyboardRestore = true;
                     break;
                 case CMD_NOP:
                     log.info(">>> NOP command");
@@ -190,6 +195,10 @@ public class DataStreamProcessor {
             screen.updateDisplaySnapshot();
         }
 
+        if (keyboardRestore && inputProcessor != null) {
+            inputProcessor.setKeyboardLocked(false);
+        }
+
         // Debug: dump non-empty screen lines
         if (log.isLoggable(Level.FINE) && (cmd == SNA_CMD_EWA || cmd == CMD_EWA || cmd == SNA_CMD_EW || cmd == CMD_EW)) {
             int r = screen.getRows();
@@ -782,22 +791,27 @@ public class DataStreamProcessor {
                 case SF_READ_PART:
                     processSFReadPartition(data, pos, fieldLen);
                     break;
-                case SF_ERASE_RESET:
+                case SF_ERASE_RESET: {
-                    if (fieldLen >= 4) {
+                    boolean alt = (fieldLen >= 4) && ((data[pos + 3] & 0xFF) == SF_ER_ALT);
-                        boolean alt = (data[pos + 3] & 0xFF) == SF_ER_ALT;
+                    screen.erase(alt);
-                        screen.erase(alt);
+                    graphicsPlane.clear();
-                        graphicsPlane.clear();
+                    gocaDecoder.resetDefaults();
-                        notifyScreenSizeChanged();
+                    notifyScreenSizeChanged();
-                    }
                     break;
+                }
                 case SF_SET_REPLY_MODE:
                     if (fieldLen >= 5) {
                         screen.setReplyMode((byte) (data[pos + 4] & 0xFF));
                     }
                     break;
                 case SF_CREATE_PART:
-                    // Acknowledged — we use implicit partition
+                    if (fieldLen >= 4) {
+                        int pid = data[pos + 3] & 0xFF;
+                        screen.setActivePartition(pid);
+                        log.fine("Created active partition ID=" + pid);
+                    }
                     graphicsPlane.clear();
+                    gocaDecoder.resetDefaults();
                     break;
                 case SF_OUTBOUND_DS:
                     if (fieldLen > 5) {
@@ -879,6 +893,13 @@ public class DataStreamProcessor {
                     }
                     break;
                 }
+                case org.lib3270j.graphics.GocaConstants.SF_OBJCNTL: // 0x24: Object Control (Procedure orders)
+                    if (fieldLen > 3) {
+                        graphicsPlane.setScreenDimensions(screen.getCols(), screen.getRows());
+                        gocaDecoder.processProcedureOrders(data, pos + 3, fieldLen - 3);
+                        notifyScreenUpdated();
+                    }
+                    break;
                 case org.lib3270j.graphics.GocaConstants.SF_OBJDATA: // 0x85: Graphics Object Data / GOCA
                 case org.lib3270j.graphics.GocaConstants.SF_3270_G:  // 0x20: 3270 Graphics
                     if (fieldLen > 3) {
@@ -915,6 +936,8 @@ public class DataStreamProcessor {
         switch (type) {
             case SF_RP_QUERY:
                 log.info("ReadPartition Query — sending all query replies");
+                graphicsPlane.clear();
+                gocaDecoder.resetDefaults();
                 sendAllQueryReplies();
                 break;
             case SF_RP_QLIST:

lib3270j/src/main/java/org/lib3270j/datastream/QueryReplyBuilder.java

@@ -197,7 +197,7 @@ public class QueryReplyBuilder {
                 case QR_RPQ_NAMES:
                 case QR_RPQNAMES:
                     if (graphicsMode.isVectorGraphicsEnabled()) {
-                        appendQueryReply(out, QR_RPQ_NAMES, buildRpqNames());
+                        appendQueryReply(out, code, buildRpqNames());
                     } else {
                         appendQueryReply(out, QR_NULL, new byte[0]);
                     }

lib3270j/src/main/java/org/lib3270j/graphics/GocaConstants.java

@@ -54,6 +54,7 @@ public final class GocaConstants {
     public static final int G_GSVW      = 0x27; // Set Viewing Window
     public static final int G_GSPT      = 0x28; // Set Pattern Symbol
     public static final int G_GSMT      = 0x29; // Set Marker Symbol / Type
+    public static final int G_GCALL     = 0x2A; // Call Segment
     public static final int G_GSCH      = 0x33; // Set Character Cell
     public static final int G_GSCA      = 0x34; // Set Character Angle
     public static final int G_GSCR      = 0x35; // Set Character Shear
@@ -176,6 +177,9 @@ public final class GocaConstants {
      * Returns Green (0xFF00FF00) if the index is out of range.
      */
     public static int getGocaColorArgb(int colorIndex) {
+        if (colorIndex == 0xFF) {
+            return GOCA_COLORS[7];
+        }
         if (colorIndex >= 0 && colorIndex < GOCA_COLORS.length) {
             return GOCA_COLORS[colorIndex];
         }

lib3270j/src/main/java/org/lib3270j/graphics/GocaDecoder.java

@@ -20,6 +20,8 @@ public class GocaDecoder {
     private int curX = 0;
     private int curY = 0;
     private int curColor = GocaConstants.GOCA_COLORS[0];
+    private int bgMix = 2; // BMX_OVERPAINT default
+    private int bgColor = GocaConstants.GOCA_COLORS[8]; // Black
     private int lineType = GocaConstants.LT_SOLID;
     private int lineWidth = GocaConstants.LW_NORMAL;
     private int markerType = GocaConstants.MK_PLUS;
@@ -42,6 +44,7 @@ public class GocaDecoder {
     // Area accumulation
     private boolean inArea = false;
     private boolean areaDrawBoundary = true;
+    private boolean areaFill = true;
     private final List<Integer> areaPointsX = new ArrayList<>();
     private final List<Integer> areaPointsY = new ArrayList<>();
 
@@ -53,6 +56,18 @@ public class GocaDecoder {
     private int imgHeight = 0;
     private final List<Byte> imgBuffer = new ArrayList<>();
 
+    // Segment Store for retained graphics / segment calling (G_GCALL 0x2A)
+    private final java.util.Map<Integer, byte[]> segmentStore = new java.util.HashMap<>();
+    private final java.util.Map<Integer, Integer> segmentChainMap = new java.util.HashMap<>();
+    private final java.util.List<Integer> segmentOrderList = new java.util.ArrayList<>();
+    private final java.util.Set<Integer> chainedTargets = new java.util.HashSet<>();
+    private int callDepth = 0;
+
+    // Graphic Cursor (Light-Pen) state
+    private boolean graphicsCursorActive = false;
+    private int graphicCursorX = 0;
+    private int graphicCursorY = 0;
+
     public GocaDecoder(GraphicsPlane plane) {
         this.plane = plane;
     }
@@ -73,14 +88,51 @@ public class GocaDecoder {
         return curY;
     }
 
+    public synchronized boolean isGraphicsCursorActive() {
+        return graphicsCursorActive;
+    }
+
+    public synchronized void setGraphicsCursorActive(boolean active) {
+        this.graphicsCursorActive = active;
+    }
+
+    public synchronized int getGraphicCursorX() {
+        return graphicCursorX;
+    }
+
+    public synchronized int getGraphicCursorY() {
+        return graphicCursorY;
+    }
+
+    public synchronized void setGraphicCursorPosition(int x, int y) {
+        this.graphicCursorX = x;
+        this.graphicCursorY = y;
+    }
+
+    public synchronized void setGraphicCursorFromPixel(int px, int py) {
+        if (plane != null) {
+            this.graphicCursorX = plane.unmapX(px);
+            this.graphicCursorY = plane.unmapY(py);
+        }
+    }
+
     public synchronized void resetDefaults() {
         curX = 0;
         curY = 0;
+        graphicsCursorActive = false;
+        graphicCursorX = 0;
+        graphicCursorY = 0;
+        segmentStore.clear();
+        segmentChainMap.clear();
+        segmentOrderList.clear();
+        chainedTargets.clear();
         resetAttributes();
     }
 
     public synchronized void resetAttributes() {
         curColor = getColor(0);
+        bgMix = 2; // BMX_OVERPAINT
+        bgColor = GocaConstants.GOCA_COLORS[8]; // Black
         lineType = GocaConstants.LT_SOLID;
         lineWidth = GocaConstants.LW_NORMAL;
         markerType = GocaConstants.MK_PLUS;
@@ -92,6 +144,8 @@ public class GocaDecoder {
         charAngle = 0.0;
         charSet = 0;
         inArea = false;
+        areaDrawBoundary = true;
+        areaFill = true;
         areaPointsX.clear();
         areaPointsY.clear();
         inImage = false;
@@ -115,14 +169,14 @@ public class GocaDecoder {
             order == GocaConstants.G_GSBMX || order == GocaConstants.G_GSFLW ||
             order == GocaConstants.G_GSLT || order == GocaConstants.G_GSLW ||
             order == GocaConstants.G_GSMS || order == GocaConstants.G_GSPT ||
-            order == GocaConstants.G_GSMT || order == GocaConstants.G_GSCS ||
+            order == GocaConstants.G_GSMT || order == GocaConstants.G_GSMCEL ||
-            order == GocaConstants.G_GSMP || order == GocaConstants.G_GSCD ||
+            order == GocaConstants.G_GSCS || order == GocaConstants.G_GSMP ||
-            order == GocaConstants.G_GSCC || order == GocaConstants.G_GSMS_SET ||
+            order == GocaConstants.G_GSCD || order == GocaConstants.G_GSCC ||
-            order == GocaConstants.G_GBAR) {
+            order == GocaConstants.G_GSMS_SET || order == GocaConstants.G_GBAR) {
             return 2;
         }
-        if (order == GocaConstants.G_GSAP || order == GocaConstants.G_GBIMG || order == 0x91) {
+        if (order == GocaConstants.G_GCALL) { // Call Segment (0x2A <32-bit segment ID>)
-            return 10;
+            return 5;
         }
         if (idx + 1 >= end) {
             return -1;
@@ -130,6 +184,61 @@ public class GocaDecoder {
         return (data[idx + 1] & 0xFF) + 2;
     }
 
+    private void indexSegments(byte[] data, int offset, int length) {
+        int idx = offset;
+        int end = offset + length;
+        while (idx < end) {
+            int order = data[idx] & 0xFF;
+            if (order == GocaConstants.G_BEGSEGM) {
+                int segStart = idx;
+                int segLen = getOrderLength(data, idx, end);
+                if (segLen <= 0 || idx + 5 >= end) {
+                    break;
+                }
+                int segId = ((data[idx + 2] & 0xFF) << 24) |
+                            ((data[idx + 3] & 0xFF) << 16) |
+                            ((data[idx + 4] & 0xFF) << 8)  |
+                            (data[idx + 5] & 0xFF);
+
+                int nextId = 0;
+                if (segLen >= 14 && (data[idx + 1] & 0xFF) >= 12) {
+                    nextId = ((data[idx + 10] & 0xFF) << 24) |
+                             ((data[idx + 11] & 0xFF) << 16) |
+                             ((data[idx + 12] & 0xFF) << 8)  |
+                             (data[idx + 13] & 0xFF);
+                }
+
+                int searchIdx = idx + segLen;
+                while (searchIdx < end) {
+                    int o = data[searchIdx] & 0xFF;
+                    int oLen = getOrderLength(data, searchIdx, end);
+                    if (oLen <= 0) break;
+                    if (o == GocaConstants.G_ENDSEGM) {
+                        searchIdx += oLen;
+                        break;
+                    }
+                    searchIdx += oLen;
+                }
+                int fullSegLen = searchIdx - segStart;
+                if (fullSegLen > 0 && segStart + fullSegLen <= end) {
+                    byte[] segBytes = new byte[fullSegLen];
+                    System.arraycopy(data, segStart, segBytes, 0, fullSegLen);
+                    segmentStore.put(segId, segBytes);
+                    segmentOrderList.add(segId);
+                    if (nextId != 0) {
+                        segmentChainMap.put(segId, nextId);
+                        chainedTargets.add(nextId);
+                    }
+                }
+                idx = searchIdx;
+            } else {
+                int oLen = getOrderLength(data, idx, end);
+                if (oLen <= 0) break;
+                idx += oLen;
+            }
+        }
+    }
+
     /**
      * Decodes a stream of GOCA drawing orders.
      */
@@ -155,6 +264,15 @@ public class GocaDecoder {
             end = offset + length;
         }
 
+        if (callDepth == 0) {
+            indexSegments(inputData, idx, end - idx);
+        }
+
+        decodeStreamDirect(inputData, idx, end - idx);
+    }
+
+    private void decodeStreamDirect(byte[] inputData, int idx, int length) {
+        int end = idx + length;
         while (idx < end) {
             int order = inputData[idx] & 0xFF;
             int orderLen = getOrderLength(inputData, idx, end);
@@ -225,6 +343,22 @@ public class GocaDecoder {
                     idx += orderLen;
                     break;
                 }
+                case GocaConstants.G_GCALL: { // Call Segment (0x2A)
+                    if (callDepth < 16 && idx + 4 < end) {
+                        int targetSegId = ((inputData[idx + 1] & 0xFF) << 24) |
+                                          ((inputData[idx + 2] & 0xFF) << 16) |
+                                          ((inputData[idx + 3] & 0xFF) << 8)  |
+                                          (inputData[idx + 4] & 0xFF);
+                        byte[] targetSeg = segmentStore.get(targetSegId);
+                        if (targetSeg != null) {
+                            callDepth++;
+                            decodeStream(targetSeg, 0, targetSeg.length);
+                            callDepth--;
+                        }
+                    }
+                    idx += orderLen;
+                    break;
+                }
                 case GocaConstants.G_GSCA: { // Set Character Angle (0x34)
                     if (payloadLen >= 4 && idx + 5 < end) {
                         int ax = readCoord(inputData, idx + 2);
@@ -312,7 +446,6 @@ public class GocaDecoder {
                 }
                 case 0x04:
                 case GocaConstants.G_GSMX:
-                case GocaConstants.G_GSBMX:
                 case GocaConstants.G_GSFLW:
                 case GocaConstants.G_GSMP:
                 case GocaConstants.G_GSCC:
@@ -321,9 +454,17 @@ public class GocaDecoder {
                     idx += orderLen;
                     break;
                 }
+                case GocaConstants.G_GSBMX: { // Set Background Mix (0x0D)
+                    bgMix = inputData[idx + 1] & 0xFF;
+                    idx += orderLen;
+                    break;
+                }
                 case GocaConstants.G_GBAR: { // Begin Area (0x68)
                     int flags = inputData[idx + 1] & 0xFF;
-                    beginArea((flags & 0x40) != 0);
+                    boolean drawBoundary = (flags & 0x80) != 0 || (flags == 0);
+                    boolean fill = (flags == 0) || (flags & 0x40) != 0 ||
+                                   (pattern >= 1 && pattern <= 14);
+                    beginArea(drawBoundary, fill);
                     idx += orderLen;
                     break;
                 }
@@ -426,7 +567,7 @@ public class GocaDecoder {
                     break;
                 }
                 case GocaConstants.G_GBIMG: { // Begin Image (0xD1)
-                    if (idx + 9 < end) {
+                    if (payloadLen >= 8 && idx + 2 + payloadLen <= end) {
                         int x = readCoord(inputData, idx + 2);
                         int y = readCoord(inputData, idx + 4);
                         int w = readCoord(inputData, idx + 6);
@@ -468,41 +609,57 @@ public class GocaDecoder {
             int order = data[idx] & 0xFF;
 
             switch (order) {
-                case GocaConstants.P_NOP1:
+                case GocaConstants.P_NOP1: {
-                case GocaConstants.P_ATTCUR:
+                    idx += (idx + 1 < end && data[idx + 1] == 0) ? 2 : 1;
-                case GocaConstants.P_DETCUR:
+                    break;
+                }
+                case GocaConstants.P_ATTCUR: { // 0x08: Attach Graphic Cursor
+                    this.graphicsCursorActive = true;
+                    idx += 2;
+                    break;
+                }
+                case GocaConstants.P_DETCUR: { // 0x09: Detach Graphic Cursor
+                    this.graphicsCursorActive = false;
+                    idx += 2;
+                    break;
+                }
                 case GocaConstants.P_STOPDR: {
-                    idx++;
+                    idx += 2;
                     break;
                 }
                 case GocaConstants.P_ERASE: { // 0x0A: Erase Graphics Presentation Space
                     plane.clear();
                     resetDefaults();
-                    idx++;
+                    idx += 2;
                     break;
                 }
                 case GocaConstants.P_BEGPROC: { // 0x30: Begin Procedure (length 12)
-                    int len = 12;
+                    idx += 12;
-                    if (idx + 1 < end && data[idx + 1] != 0) {
-                        len = (data[idx + 1] & 0xFF) + 2;
-                    }
-                    idx += len;
                     break;
                 }
-                case GocaConstants.P_SCUDEF: { // 0x21: Set Current Defaults
+                case GocaConstants.P_SCUDEF: { // 0x21: Drawing Process Control / Segment Execute
+                    if (idx + 1 < end) {
+                        int len = (data[idx + 1] & 0xFF) + 2;
+                        idx += len;
+                    } else {
+                        idx++;
+                    }
+                    break;
+                }
+                case GocaConstants.P_SETCUR: { // 0x31: Set Graphic Cursor Position
+                    if (idx + 5 <= end) {
+                        this.graphicCursorX = readCoord(data, idx + 2);
+                        this.graphicCursorY = readCoord(data, idx + 4);
+                    }
                     if (idx + 1 < end) {
                         int len = data[idx + 1] & 0xFF;
-                        if (idx + 2 + len <= end) {
-                            decodeStream(data, idx + 2, len);
-                        }
                         idx += 2 + len;
                     } else {
                         idx++;
                     }
                     break;
                 }
-                case GocaConstants.P_COMT:
+                case GocaConstants.P_COMT: {
-                case GocaConstants.P_SETCUR: {
                     if (idx + 1 < end) {
                         int len = data[idx + 1] & 0xFF;
                         idx += 2 + len;
@@ -524,9 +681,10 @@ public class GocaDecoder {
         }
     }
 
-    private void beginArea(boolean drawBoundary) {
+    private void beginArea(boolean drawBoundary, boolean fill) {
         this.inArea = true;
         this.areaDrawBoundary = drawBoundary;
+        this.areaFill = fill;
         this.fillColor = this.curColor;
         this.areaPointsX.clear();
         this.areaPointsY.clear();
@@ -547,7 +705,8 @@ public class GocaDecoder {
             py[i] = plane.mapY(areaPointsY.get(i));
         }
 
-        plane.fillArea(px, py, n, fillColor, pattern, areaDrawBoundary, curColor, lineType, lineWidth);
+        plane.fillArea(px, py, n, fillColor, areaFill ? pattern : GocaConstants.PT_EMPTY,
+                       areaDrawBoundary, curColor, lineType, lineWidth, bgMix, bgColor);
         inArea = false;
         areaPointsX.clear();
         areaPointsY.clear();
@@ -555,8 +714,11 @@ public class GocaDecoder {
 
     private void addAreaPoint(int x, int y) {
         if (inArea) {
-            areaPointsX.add(x);
+            int sz = areaPointsX.size();
-            areaPointsY.add(y);
+            if (sz == 0 || areaPointsX.get(sz - 1) != x || areaPointsY.get(sz - 1) != y) {
+                areaPointsX.add(x);
+                areaPointsY.add(y);
+            }
         }
     }
 

lib3270j/src/main/java/org/lib3270j/graphics/GraphicInputBuilder.java

@@ -0,0 +1,59 @@
+package org.lib3270j.graphics;
+
+/**
+ * Builds the 56-byte IBM 3179G / 3270G Graphic Input Structured Field.
+ * Used for light-pen and graphics cursor interactive input per IBM HOD / GDDM specifications.
+ */
+public class GraphicInputBuilder {
+
+    // 56-byte template mask from IBM Host On-Demand (HODInput.java)
+    private static final byte[] MASK = new byte[] {
+        0x00, 0x34, 0x0F, 0x0F, 0x00, (byte) 0xC0, 0x00, 0x40,
+        0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x23, 0x00, 0x23, 0x00, 0x00, 0x00, 0x1F, 0x01,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
+        0x00, 0x04, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, (byte) 0x80, 0x00
+    };
+
+    /**
+     * Builds the 56-byte Graphic Input Structured Field.
+     *
+     * @param gocaX GOCA signed X coordinate (-xMax..+xMax)
+     * @param gocaY GOCA signed Y coordinate (-yMax..+yMax)
+     * @param aidCode The 3270 AID code (e.g. 0x7D for ENTER, 0xF3 for PF3)
+     * @param isMouseAction true if triggered directly by mouse button press, false for keyboard AID
+     * @param isShift true if shift key was down
+     * @param isCtrl true if ctrl key was down
+     * @return 56-byte payload
+     */
+    public static byte[] buildGraphicInput(int gocaX, int gocaY, int aidCode,
+                                          boolean isMouseAction, boolean isShift, boolean isCtrl) {
+        byte[] sf = new byte[MASK.length];
+        System.arraycopy(MASK, 0, sf, 0, MASK.length);
+
+        // Byte 24-25: GOCA X coordinate (signed 16-bit big-endian)
+        sf[24] = (byte) ((gocaX >> 8) & 0xFF);
+        sf[25] = (byte) (gocaX & 0xFF);
+
+        // Byte 26-27: GOCA Y coordinate (signed 16-bit big-endian)
+        sf[26] = (byte) ((gocaY >> 8) & 0xFF);
+        sf[27] = (byte) (gocaY & 0xFF);
+
+        if (isMouseAction) {
+            sf[31] = 0x04;
+            sf[33] = 0x04;
+            sf[34] = isShift ? (byte) 0x80 : (isCtrl ? (byte) 0x40 : 0x00);
+            sf[35] = (byte) (aidCode == 2 ? 0x02 : 0x01); // Button 1 = Pick
+        } else {
+            // Keyboard AID (Enter, PF keys)
+            sf[31] = 0x07;
+            sf[33] = 0x07;
+            sf[34] = (byte) 0xFF;
+            sf[35] = (byte) (aidCode & 0xFF);
+        }
+
+        return sf;
+    }
+}

lib3270j/src/main/java/org/lib3270j/graphics/GraphicsPlane.java

@@ -97,9 +97,14 @@ public class GraphicsPlane {
         return canvasHeight;
     }
 
-    public void setScreenDimensions(int cols, int rows) {
+    public synchronized void setScreenDimensions(int cols, int rows) {
         this.screenCols = cols > 0 ? cols : 80;
         this.screenRows = rows > 0 ? rows : 24;
+        int targetW = this.screenCols * 9;
+        int targetH = this.screenRows * 12;
+        if (this.canvasWidth != targetW || this.canvasHeight != targetH) {
+            resize(targetW, targetH);
+        }
     }
 
     public int getScreenCols() {
@@ -124,12 +129,32 @@ public class GraphicsPlane {
      * Maps a 3179G / GOCA signed coordinate (centered at screen midpoint, bottom-up) to canvas pixel Y (top-down).
      */
     public int mapY(int gocaY) {
-        int nominalHeight = screenRows * 16;
+        int nominalHeight = screenRows * 12;
         int yMax = (nominalHeight - 1) / 2;
         int ny = yMax - gocaY;
         return (int) Math.round((double) ny * canvasHeight / nominalHeight);
     }
 
+    /**
+     * Maps a canvas pixel X coordinate back to GOCA signed coordinate (-xMax..+xMax).
+     */
+    public int unmapX(int px) {
+        int nominalWidth = screenCols * 9;
+        int xMax = (nominalWidth - 1) / 2 + ((nominalWidth - 1) % 2 != 0 ? 1 : 0);
+        int nx = (int) Math.round((double) px * nominalWidth / (canvasWidth > 0 ? canvasWidth : 1));
+        return nx - xMax;
+    }
+
+    /**
+     * Maps a canvas pixel Y coordinate (top-down) back to GOCA signed coordinate (bottom-up).
+     */
+    public int unmapY(int py) {
+        int nominalHeight = screenRows * 12;
+        int yMax = (nominalHeight - 1) / 2;
+        int ny = (int) Math.round((double) py * nominalHeight / (canvasHeight > 0 ? canvasHeight : 1));
+        return yMax - ny;
+    }
+
     /**
      * Safely plots a pixel at (x, y).
      */
@@ -286,9 +311,19 @@ public class GraphicsPlane {
      */
     public synchronized void fillArea(int[] px, int[] py, int numPoints, int fillColorArgb, int pattern,
                                       boolean drawBoundary, int boundaryColorArgb, int lineType, int lineWidth) {
+        fillArea(px, py, numPoints, fillColorArgb, pattern, drawBoundary, boundaryColorArgb, lineType, lineWidth, 2, 0xFF000000);
+    }
+
+    /**
+     * Fills a closed polygon area with a solid color or hatching pattern and background mix.
+     */
+    public synchronized void fillArea(int[] px, int[] py, int numPoints, int fillColorArgb, int pattern,
+                                      boolean drawBoundary, int boundaryColorArgb, int lineType, int lineWidth,
+                                      int bgMix, int bgColorArgb) {
         if (px == null || py == null || numPoints < 3) return;
 
         int fill = (fillColorArgb != 0) ? fillColorArgb : 0xFFFFFFFF;
+        int bg = bgColorArgb;
 
         if (pattern != GocaConstants.PT_EMPTY) {
             // Find polygon vertical bounds
@@ -323,12 +358,14 @@ public class GraphicsPlane {
                     int rightX = Math.min(canvasWidth - 1, nodeX.get(i + 1));
 
                     for (int x = leftX; x <= rightX; x++) {
-                        if (pattern == GocaConstants.PT_SOLID || pattern == GocaConstants.PT_DEFAULT || pattern > 16) {
+                        if (pattern == GocaConstants.PT_SOLID || pattern >= 16) {
                             setPixel(x, y, fill);
                         } else {
                             int b = patRows[y & 7] & 0xFF;
                             if (((b >> (7 - (x & 7))) & 1) != 0) {
                                 setPixel(x, y, fill);
+                            } else if (bgMix != 0) { // BMX_OVERPAINT (opaque background)
+                                setPixel(x, y, bg);
                             }
                         }
                     }
@@ -506,13 +543,14 @@ public class GraphicsPlane {
     public synchronized void drawImage(int x, int y, int width, int height, byte[] imageData, int fgColorArgb) {
         if (imageData == null || width <= 0 || height <= 0) return;
         int fgColor = (fgColorArgb != 0) ? fgColorArgb : 0xFFFFFFFF;
+        int bytesPerRow = (width + 7) / 8;
 
         for (int row = 0; row < height; row++) {
+            int rowOffset = row * bytesPerRow;
             for (int col = 0; col < width; col++) {
-                int bitIndex = row * width + col;
+                int byteIdx = rowOffset + (col / 8);
-                int byteIdx = bitIndex / 8;
                 if (byteIdx < imageData.length) {
-                    boolean bit = ((imageData[byteIdx] >> (7 - (bitIndex % 8))) & 1) != 0;
+                    boolean bit = ((imageData[byteIdx] >> (7 - (col % 8))) & 1) != 0;
                     if (bit) {
                         setPixel(x + col, y + row, fgColor);
                     }

lib3270j/src/main/java/org/lib3270j/graphics/ProgramSymbolManager.java

@@ -87,8 +87,11 @@ public class ProgramSymbolManager {
         }
         ProgramSymbolSet set = lcidMap[lcid];
         if (set == null) {
+            for (ProgramSymbolSet s : sets) {
+                if (s != null && s.getLcid() == lcid) return s;
+            }
             for (ProgramSymbolSet s : stagingSets) {
-                if (s.getLcid() == lcid) return s;
+                if (s != null && s.getLcid() == lcid) return s;
             }
         }
         return set;
@@ -98,18 +101,7 @@ public class ProgramSymbolManager {
      * Retrieves a specific symbol glyph by LCID and character code point (0x40 - 0xFE).
      */
     public ProgramSymbolSet.SymbolSlot getSymbol(int lcid, int codePoint) {
-        if (lcid <= 0 || lcid >= 256) {
+        ProgramSymbolSet set = getSymbolSet(lcid);
-            return null;
-        }
-        ProgramSymbolSet set = lcidMap[lcid];
-        if (set == null) {
-            for (ProgramSymbolSet s : stagingSets) {
-                if (s.getLcid() == lcid) {
-                    set = s;
-                    break;
-                }
-            }
-        }
         if (set == null) {
             return null;
         }
@@ -153,7 +145,7 @@ public class ProgramSymbolManager {
         }
 
         boolean isTriplePlane = (rws >= 4 && rws <= 7);
-        ProgramSymbolSet set = isTriplePlane ? stagingSets[setIndex] : sets[setIndex];
+        ProgramSymbolSet set = sets[setIndex];
 
         int extHeaderLen = 0;
         int cellWidth = defaultCellWidth;
@@ -176,7 +168,7 @@ public class ProgramSymbolManager {
         }
 
         set.setLcid(lcid);
-        if (!isTriplePlane && lcid > 0 && lcid < 256) {
+        if (lcid > 0 && lcid < 256) {
             lcidMap[lcid] = set;
         }
 

lib3270j/src/main/java/org/lib3270j/input/InputProcessor.java

@@ -32,11 +32,20 @@ public class InputProcessor {
     }
 
     private org.lib3270j.graphics.GraphicsPlane graphicsPlane;
+    private org.lib3270j.graphics.GocaDecoder gocaDecoder;
 
     public void setGraphicsPlane(org.lib3270j.graphics.GraphicsPlane gp) {
         this.graphicsPlane = gp;
     }
 
+    public void setGocaDecoder(org.lib3270j.graphics.GocaDecoder gd) {
+        this.gocaDecoder = gd;
+    }
+
+    public org.lib3270j.graphics.GocaDecoder getGocaDecoder() {
+        return gocaDecoder;
+    }
+
     public enum OiaStatus {
         NOT_CONNECTED("OFFLINE"),
         X_SYSTEM("X SYSTEM"),
@@ -159,7 +168,11 @@ public class InputProcessor {
      * Send an AID key (Enter, PF1-24, PA1-3, Clear).
      */
     public void sendAid(int aidCode) {
-        if (keyboardLocked && aidCode != AID_CLEAR) return;
+        System.err.println("sendAid called: 0x" + Integer.toHexString(aidCode) + " locked=" + keyboardLocked);
+        if (keyboardLocked && aidCode != AID_CLEAR) {
+            System.err.println("Keyboard locked, dropping AID");
+            return;
+        }
 
         lastAid = aidCode;
         setKeyboardLocked(true);
@@ -213,15 +226,30 @@ public class InputProcessor {
         }
 
         if (aidCode == AID_PA1 || aidCode == AID_PA2 || aidCode == AID_PA3) {
-            // PA keys: send AID + cursor address only (no modified data)
+            // PA keys: send AID + optional PID + cursor address only (no modified data)
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            out.write(aidCode);
             byte[] caddr = encodeAddress(screen.getCursorAddress(), screen.getRows(), screen.getCols());
-            byte[] data = new byte[] { (byte) aidCode, caddr[0], caddr[1] };
+            out.write(caddr[0] & 0xFF);
-            sendAidResponse(data);
+            out.write(caddr[1] & 0xFF);
+            sendAidResponse(out.toByteArray());
             return;
         }
 
-        // Enter, PF keys: send AID + cursor address + modified field data
+        // Enter, PF keys, PA keys: send AID + optional PID + cursor address + modified field data
         ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+        // If GDDM attached graphic cursor (interactive graphics / light-pen mode):
+        if (gocaDecoder != null && gocaDecoder.isGraphicsCursorActive() && aidCode != AID_CLEAR) {
+            int gx = gocaDecoder.getGraphicCursorX();
+            int gy = gocaDecoder.getGraphicCursorY();
+            byte[] sf = org.lib3270j.graphics.GraphicInputBuilder.buildGraphicInput(gx, gy, aidCode, false, false, false);
+            out.write(AID_SF); // 0x88
+            try {
+                out.write(sf);
+            } catch (java.io.IOException ignored) {}
+        }
+
         out.write(aidCode);
 
         byte[] caddr = encodeAddress(screen.getCursorAddress(), screen.getRows(), screen.getCols());
@@ -267,28 +295,16 @@ public class InputProcessor {
                 }
             }
         } else {
-            // Unformatted screen in 3270 mode (e.g. line-mode console):
+            // Unformatted screen in 3270 mode:
-            // Send AID + cursor address + only the active input line (row containing cursor)
+            // Send AID + cursor address + all non-null characters on the screen, suppressing trailing nulls per line
-            int cols = screen.getCols();
+            // or we can just send everything up to the last non-null on the screen.
-            int curAddr = screen.getCursorAddress();
+            // IBM spec: "all alphanumeric characters... Nulls are suppressed."
-            int row = curAddr / cols;
+            // Actually, the simplest is to send everything, but suppress nulls.
-            int rowStart = row * cols;
+            int size = screen.getRows() * screen.getCols();
-            int rowEnd = rowStart + cols;
+            for (int i = 0; i < size; i++) {
-
+                int b = screen.getCell(i).ec & 0xFF;
-            // Find last non-null, non-blank character on the current line
+                if (b != 0x00) {
-            int lastChar = rowStart - 1;
+                    out.write(b);
-            for (int i = rowEnd - 1; i >= rowStart; i--) {
-                int ec = screen.getCell(i).ec & 0xFF;
-                if (ec != 0x00 && ec != 0x40) {
-                    lastChar = i;
-                    break;
-                }
-            }
-
-            if (lastChar >= rowStart) {
-                for (int i = rowStart; i <= lastChar; i++) {
-                    int b = screen.getCell(i).ec & 0xFF;
-                    out.write(b != 0 ? b : 0x40);
                 }
             }
         }
@@ -304,6 +320,36 @@ public class InputProcessor {
         }
     }
 
+    /**
+     * Transmit a mouse / light-pen graphic input AID matching IBM Host On-Demand PS3179G.
+     */
+    public void sendGraphicMouseAid(int aidCode, int button, boolean isShift, boolean isCtrl) {
+        if (fsm == null || !fsm.getConnectionState().isFullSession()) {
+            return;
+        }
+        if (isKeyboardLocked()) {
+            return;
+        }
+        setKeyboardLocked(true);
+
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        if (gocaDecoder != null && gocaDecoder.isGraphicsCursorActive()) {
+            int gx = gocaDecoder.getGraphicCursorX();
+            int gy = gocaDecoder.getGraphicCursorY();
+            byte[] sf = org.lib3270j.graphics.GraphicInputBuilder.buildGraphicInput(gx, gy, aidCode, true, isShift, isCtrl);
+            out.write(AID_SF);
+            try {
+                out.write(sf);
+            } catch (java.io.IOException ignored) {}
+        }
+        out.write(aidCode);
+        byte[] caddr = encodeAddress(screen.getCursorAddress(), screen.getRows(), screen.getCols());
+        out.write(caddr[0] & 0xFF);
+        out.write(caddr[1] & 0xFF);
+
+        sendAidResponse(out.toByteArray());
+    }
+
     // ========== Cursor movement ==========
 
     public void cursorUp() {

lib3270j/src/main/java/org/lib3270j/protocol/TelnetConstants.java

@@ -76,6 +76,7 @@ public final class TelnetConstants {
             case TELOPT_BINARY:      return "BINARY";
             case TELOPT_ECHO:        return "ECHO";
             case TELOPT_SGA:         return "SGA";
+            case TELOPT_TM:          return "TIMING-MARK";
             case TELOPT_TTYPE:       return "TTYPE";
             case TELOPT_EOR:         return "EOR";
             case TELOPT_NAWS:        return "NAWS";

lib3270j/src/main/java/org/lib3270j/screen/ScreenBuffer.java

@@ -24,6 +24,9 @@ public class ScreenBuffer {
     private boolean screenAlt;        // Using alternate screen?
     private boolean formatted;        // Screen has at least one field attribute?
     private byte replyMode = SF_SRM_FIELD;
+    
+    private int activePartition = 0; // 0 = implicit partition
+    private boolean explicitPartitionActive = false;
 
     // Change tracking
     private boolean screenChanged;
@@ -167,6 +170,10 @@ public class ScreenBuffer {
 
     public byte getReplyMode()                     { return replyMode; }
     public void setReplyMode(byte mode)            { this.replyMode = mode; }
+    
+    public int getActivePartition()                { return activePartition; }
+    public void setActivePartition(int pid)        { this.activePartition = pid; this.explicitPartitionActive = true; }
+    public boolean isExplicitPartitionActive()     { return explicitPartitionActive; }
 
     // ========== Screen erase ==========
 
@@ -187,6 +194,19 @@ public class ScreenBuffer {
         updateDisplaySnapshot();
     }
 
+    public void setFieldAttribute(int pos, byte fa) {
+        ExtendedAttribute ea = buffer[pos];
+        ea.clear();
+        ea.fa = fa;
+        if (!formatted) {
+            System.err.println("SCREEN BECAME FORMATTED at pos " + pos);
+        }
+        formatted = true;
+        screenChanged = true;
+        // The display logic needs to render this attribute character
+        ea.ec = 0x00; // Typically null character for the attribute space itself
+    }
+
     /** Clear the entire buffer. */
     public synchronized void clear() {
         for (ExtendedAttribute ea : buffer) {
@@ -195,6 +215,9 @@ public class ScreenBuffer {
         cursorAddress = 0;
         bufferAddress = 0;
         formatted = false;
+        replyMode = SF_SRM_FIELD;
+        activePartition = 0;
+        explicitPartitionActive = false;
         screenChanged = true;
 
         defaultFg = 0x00;

lib3270j/src/main/java/org/lib3270j/telnet/TelnetFSM.java

@@ -8,6 +8,7 @@ import org.lib3270j.listener.*;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.logging.Logger;
@@ -59,6 +60,32 @@ public class TelnetFSM {
     private int responseRequired = RSF_NO_RESPONSE;
     private boolean deferredWillTtype;
     private boolean tn3270eDeviceTypeSent;
+    private int ttypeIndex = 0;
+
+    private List<String> getCandidateTerminalTypes() {
+        List<String> list = new ArrayList<>();
+        if (config.getTerminalName() != null && !config.getTerminalName().trim().isEmpty()) {
+            list.add(config.getTerminalName().trim());
+            return list;
+        }
+        TerminalModel model = config.getModel();
+        list.add(model.getTerminalType());
+        list.add(model.getBaseTerminalType());
+        if (model.isColor()) {
+            try {
+                TerminalModel mono = TerminalModel.forModel(model.getModelNumber(), false);
+                list.add(mono.getTerminalType());
+                list.add(mono.getBaseTerminalType());
+            } catch (Exception ignored) {}
+        }
+        if (model.getModelNumber() != 2) {
+            list.add("IBM-3279-2-E");
+            list.add("IBM-3279-2");
+            list.add("IBM-3278-2");
+        }
+        list.add("UNKNOWN");
+        return list;
+    }
 
     // Connection references
     private TelnetConnection connection;
@@ -109,6 +136,7 @@ public class TelnetFSM {
         tn3270eBound = false;
         eXmitSeq = 0;
         deferredWillTtype = false;
+        ttypeIndex = 0;
         ibuf.reset();
         sbbuf.reset();
 
@@ -116,6 +144,9 @@ public class TelnetFSM {
         eFuncs[FUNC_BIND_IMAGE] = true;
         eFuncs[FUNC_RESPONSES] = true;
         eFuncs[FUNC_SYSREQ] = true;
+        eFuncs[FUNC_SNA_SENSE] = true;
+        eFuncs[FUNC_DATA_STREAM_CTL] = true;
+        eFuncs[FUNC_CONTENTION_RESOLUTION] = true;
 
         changeState(ConnectionState.TELNET_PENDING);
     }
@@ -240,6 +271,11 @@ public class TelnetFSM {
                 log.fine("RCVD GA");
                 state = TNS_DATA;
                 break;
+            case AYT:
+                log.info("RCVD AYT - sending acknowledgment");
+                sendBytes(new byte[] { (byte) IAC, (byte) NOP });
+                state = TNS_DATA;
+                break;
             case NOP:
                 log.fine("RCVD NOP");
                 state = TNS_DATA;
@@ -267,6 +303,11 @@ public class TelnetFSM {
                 }
                 break;
 
+            case TELOPT_TM:
+                // RFC 860: Timing Mark - reply with DO TM
+                sendCommand(DO, opt);
+                break;
+
             case TELOPT_TN3270E:
                 if (!config.isTn3270eEnabled()) {
                     sendCommand(DONT, opt);
@@ -310,6 +351,11 @@ public class TelnetFSM {
                 }
                 break;
 
+            case TELOPT_TM:
+                // RFC 860: Timing Mark - reply with WILL TM
+                sendCommand(WILL, opt);
+                break;
+
             case TELOPT_TTYPE:
                 if (!myOpts[opt]) {
                     myOpts[opt] = true;
@@ -426,8 +472,12 @@ public class TelnetFSM {
 
     private void handleTTypeSB(byte[] data) {
         if (data.length >= 2 && data[1] == TELQUAL_SEND) {
-            // Host asks for terminal type
+            // Host asks for terminal type — cycle per RFC 1091
-            String termType = config.getEffectiveTerminalType();
+            List<String> candidates = getCandidateTerminalTypes();
+            String termType = candidates.get(Math.min(ttypeIndex, candidates.size() - 1));
+            if (ttypeIndex < candidates.size() - 1) {
+                ttypeIndex++;
+            }
             log.info("RCVD SB TTYPE SEND - Responding with: " + termType);
 
             ByteArrayOutputStream out = new ByteArrayOutputStream();
@@ -538,7 +588,7 @@ public class TelnetFSM {
             if (reason == REASON_INV_DEVICE_TYPE || reason == REASON_UNSUPPORTED_REQ) {
                 // Try fallback model 2 if we were requesting something else
                 if (config.getModel() != TerminalModel.IBM_3278_2 &&
-                    config.getModel() != TerminalModel.IBM_3279_2) {
+                    config.getModel() != TerminalModel.IBM_3279_4) {
                     log.warning("TN3270E device-type rejected (" +
                         TN3270EConstants.reasonName(reason) + "), retrying with IBM-3278-2");
                     config.setModel(TerminalModel.IBM_3278_2);
@@ -880,6 +930,23 @@ public class TelnetFSM {
                 tn3270eSubmode = TN3270ESubmode.E_NVT;
                 break;
 
+            case DT_REQUEST:
+                log.info("Received DT_REQUEST requestFlag=" + requestFlag);
+                if ((requestFlag & RQF_KEYBOARD_RESTORE) != 0) {
+                    if (dsProcessor != null && dsProcessor.getInputProcessor() != null) {
+                        dsProcessor.getInputProcessor().setKeyboardLocked(false);
+                    }
+                }
+                if ((requestFlag & RQF_SIGNAL) != 0) {
+                    for (ScreenUpdateListener l : screenListeners) {
+                        l.onSoundAlarm();
+                    }
+                }
+                if (eFuncs[FUNC_RESPONSES] && responseFlag == RSF_ALWAYS_RESPONSE) {
+                    sendTN3270EPositiveResponse(seqNumber);
+                }
+                break;
+
             case DT_RESPONSE:
                 log.fine("Received response, seq=" + seqNumber);
                 break;
@@ -903,7 +970,7 @@ public class TelnetFSM {
         }
     }
 
-    private void sendTN3270EPositiveResponse(int seqNumber) {
+    public void sendTN3270EPositiveResponse(int seqNumber) {
         byte[] resp = new byte[EH_SIZE + 1];
         resp[0] = (byte) DT_RESPONSE;
         resp[1] = 0;
@@ -915,6 +982,31 @@ public class TelnetFSM {
         sendRecord(resp);
     }
 
+    public void sendTN3270ENegativeResponse(int seqNumber, int negCode) {
+        byte[] resp = new byte[EH_SIZE + 1];
+        resp[0] = (byte) DT_RESPONSE;
+        resp[1] = 0;
+        resp[2] = (byte) RSF_NEGATIVE_RESPONSE;
+        resp[3] = (byte) ((seqNumber >> 8) & 0xFF);
+        resp[4] = (byte) (seqNumber & 0xFF);
+        resp[5] = (byte) (negCode & 0xFF);
+
+        sendRecord(resp);
+    }
+
+    public void sendTN3270ESnaSenseResponse(int seqNumber, int sense1, int sense2) {
+        byte[] resp = new byte[EH_SIZE + 2];
+        resp[0] = (byte) DT_RESPONSE;
+        resp[1] = 0;
+        resp[2] = (byte) RSF_SNA_SENSE;
+        resp[3] = (byte) ((seqNumber >> 8) & 0xFF);
+        resp[4] = (byte) (seqNumber & 0xFF);
+        resp[5] = (byte) (sense1 & 0xFF);
+        resp[6] = (byte) (sense2 & 0xFF);
+
+        sendRecord(resp);
+    }
+
     // ========== Check if we should transition to 3270 mode ==========
 
     private void checkIn3270() {

lib3270j/src/test/java/org/lib3270j/datastream/QueryReplyBuilderTest.java

@@ -232,4 +232,30 @@ public class QueryReplyBuilderTest {
         assertEquals(0x07, replies[descOffset + 49] & 0xFF);
         assertEquals(0xC0, replies[descOffset + 49 + 1] & 0xFF);
     }
+
+    @Test
+    public void testQueryReplyImageAndRpqNames() {
+        qrBuilder.setGraphicsMode(GraphicsMode.BOTH);
+        byte[] requested = new byte[] { (byte) QR_IMAGE, (byte) QR_RPQNAMES, (byte) QR_GIMAGE };
+        byte[] replies = qrBuilder.buildQueryReplies(requested, 80, 43, 80 * 43);
+
+        assertNotNull(replies);
+        assertEquals((byte) AID_SF, replies[0]);
+
+        // First SF should be QR_NULL (0xFF) because 0x82 is 3270 Image SF (not supported on 3179G)
+        int len1 = ((replies[1] & 0xFF) << 8) | (replies[2] & 0xFF);
+        assertEquals(0x81, replies[3] & 0xFF); // SFID_QREPLY
+        assertEquals(QR_NULL, replies[4] & 0xFF); // 0xFF
+
+        // Second SF should be QR_RPQNAMES (0xA1) matching requested code
+        int pos2 = 1 + len1;
+        int len2 = ((replies[pos2] & 0xFF) << 8) | (replies[pos2 + 1] & 0xFF);
+        assertEquals(0x81, replies[pos2 + 2] & 0xFF);
+        assertEquals(QR_RPQNAMES, replies[pos2 + 3] & 0xFF); // 0xA1
+
+        // Third SF should be QR_GIMAGE (0xB1)
+        int pos3 = pos2 + len2;
+        assertEquals(0x81, replies[pos3 + 2] & 0xFF);
+        assertEquals(QR_GIMAGE, replies[pos3 + 3] & 0xFF); // 0xB1
+    }
 }

lib3270j/src/test/java/org/lib3270j/graphics/GocaDecoderTest.java

@@ -158,6 +158,7 @@ public class GocaDecoderTest {
 
         byte[] stream = out.toByteArray();
         decoder.decodeStream(stream, 0, stream.length);
+
         assertTrue(plane.hasContent());
     }
 
@@ -203,7 +204,7 @@ public class GocaDecoderTest {
 
         // 0xA1: Relative Line from Current Position: (+10, +20), (-5, -10)
         out.write(GocaConstants.G_GCRLIN);
-        out.write(0x04); // len = 4 (2 steps)
+        out.write(0x04); // len = 4 (2 deltas * 2 bytes)
         out.write(0x0A); out.write(0x14); // dx = +10, dy = +20
         out.write(0xFB); out.write(0xF6); // dx = -5, dy = -10
 
@@ -217,21 +218,74 @@ public class GocaDecoderTest {
 
     @Test
     public void test3179GCoordinateMapping() {
-        GraphicsPlane plane = new GraphicsPlane(720, 688);
+        GraphicsPlane plane = new GraphicsPlane(720, 516);
         plane.setScreenDimensions(80, 43);
 
-        // Screen center (0, 0) should map to canvas center (360, 343)
+        // Screen center (0, 0) should map to canvas center (360, 257)
         assertEquals(360, plane.mapX(0));
-        assertEquals(343, plane.mapY(0));
+        assertEquals(257, plane.mapY(0));
 
         // Left edge (-360) should map to 0
         assertEquals(0, plane.mapX(-360));
         // Right edge (+359) should map to 719
         assertEquals(719, plane.mapX(359));
 
-        // Top edge (+343) should map to 0
+        // Top edge (+257) should map to 0
-        assertEquals(0, plane.mapY(343));
+        assertEquals(0, plane.mapY(257));
-        // Bottom edge (-344) should map to 687
+        // Bottom edge (-258) should map to 515
-        assertEquals(687, plane.mapY(-344));
+        assertEquals(515, plane.mapY(-258));
+    }
+
+    @Test
+    public void testImageOrdersGbimgGimdGeimg() {
+        GraphicsPlane plane = new GraphicsPlane(400, 300);
+        GocaDecoder decoder = new GocaDecoder(plane);
+
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        // G_GBIMG (0xD1): Begin Image: order, len=8, x=100, y=100, w=16, h=2
+        out.write(GocaConstants.G_GBIMG);
+        out.write(0x08);
+        out.write(0x00); out.write(0x64); // x = 100
+        out.write(0x00); out.write(0x64); // y = 100
+        out.write(0x00); out.write(0x10); // w = 16
+        out.write(0x00); out.write(0x02); // h = 2
+
+        // G_GIMD (0x92): Image Data: order, len=4, 4 bytes of bitmap (16x2 pixels = 32 bits = 4 bytes)
+        out.write(GocaConstants.G_GIMD);
+        out.write(0x04);
+        out.write(0xFF); out.write(0x00);
+        out.write(0xAA); out.write(0x55);
+
+        // G_GEIMG (0x91): End Image
+        out.write(GocaConstants.G_GEIMG);
+        out.write(0x00);
+
+        byte[] stream = out.toByteArray();
+        decoder.decodeStream(stream, 0, stream.length);
+
+        assertTrue(plane.hasContent(), "Expected plane to have content after image decoding");
+    }
+
+    @Test
+    public void testDirectObjectControlSf24() {
+        org.lib3270j.screen.ScreenBuffer sb = new org.lib3270j.screen.ScreenBuffer(
+            org.lib3270j.TerminalModel.IBM_3279_4, new org.lib3270j.charset.EbcdicTranslator());
+        org.lib3270j.datastream.DataStreamProcessor dsp = new org.lib3270j.datastream.DataStreamProcessor(
+            sb, new org.lib3270j.charset.EbcdicTranslator());
+
+        // First draw something on graphics plane
+        dsp.getGraphicsPlane().setPixel(10, 10, 0xFFFFFFFF);
+        assertTrue(dsp.getGraphicsPlane().hasContent());
+
+        // Send WSF with SF_OBJCNTL (0x24) containing P_ERASE (0x0A)
+        byte[] wsf = new byte[] {
+            (byte) org.lib3270j.protocol.DS3270Constants.CMD_WSF,
+            0x00, 0x04, // Field length = 4
+            (byte) org.lib3270j.graphics.GocaConstants.SF_OBJCNTL, // 0x24
+            (byte) org.lib3270j.graphics.GocaConstants.P_ERASE      // 0x0A
+        };
+        dsp.processRecord(wsf, 0, wsf.length, false);
+
+        assertFalse(dsp.getGraphicsPlane().hasContent(), "Expected graphics plane to be cleared after SF_OBJCNTL P_ERASE");
     }
 }

lib3270j/src/test/java/org/lib3270j/input/InputProcessorTest.java

@@ -131,4 +131,26 @@ public class InputProcessorTest {
         assertEquals(0, screen.getDisplayCell(2).ucs4);
         assertEquals('A', screen.getDisplayCell(1).ucs4);
     }
+
+    @Test
+    public void testGraphicInputBuilderStructure() {
+        byte[] sf = org.lib3270j.graphics.GraphicInputBuilder.buildGraphicInput(100, -50, AID_ENTER, false, false, false);
+        assertEquals(56, sf.length);
+        assertEquals(0x00, sf[0]);
+        assertEquals(0x34, sf[1]); // Length = 52
+        assertEquals(0x0F, sf[2]); // SF ID = 0x0F
+        assertEquals(0x0F, sf[3]); // SF ID = 0x0F
+
+        // Coordinates
+        int x = (sf[24] << 8) | (sf[25] & 0xFF);
+        int y = (sf[26] << 8) | (sf[27] & 0xFF);
+        assertEquals(100, (short) x);
+        assertEquals(-50, (short) y);
+
+        // Keyboard AID
+        assertEquals(0x07, sf[31]);
+        assertEquals(0x07, sf[33]);
+        assertEquals((byte) 0xFF, sf[34]);
+        assertEquals((byte) AID_ENTER, sf[35]);
+    }
 }

lib3270j/src/test/java/org/lib3270j/telnet/TelnetFSMTest.java

@@ -219,4 +219,79 @@ public class TelnetFSMTest {
         assertEquals('L', trans.ebcdicToUnicode(screenBuffer.getCellEC(3)));
         assertEquals('O', trans.ebcdicToUnicode(screenBuffer.getCellEC(4)));
     }
+
+    @Test
+    public void testTelnetTimingMarkOption6() {
+        fsm.onConnected();
+        connection.sentData.clear();
+
+        // Host sends DO TELOPT_TM (DO 6) -> Client must reply WILL TELOPT_TM (WILL 6) per RFC 860
+        feedBytes(TelnetConstants.IAC, TelnetConstants.DO, TelnetConstants.TELOPT_TM);
+        boolean foundWillTm = false;
+        for (byte[] pkt : connection.sentData) {
+            if (pkt.length == 3 && (pkt[0] & 0xFF) == TelnetConstants.IAC &&
+                (pkt[1] & 0xFF) == TelnetConstants.WILL && (pkt[2] & 0xFF) == TelnetConstants.TELOPT_TM) {
+                foundWillTm = true;
+            }
+        }
+        assertTrue(foundWillTm, "Expected IAC WILL TELOPT_TM reply upon receiving IAC DO TELOPT_TM");
+
+        // Host sends WILL TELOPT_TM (WILL 6) -> Client must reply DO TELOPT_TM (DO 6)
+        connection.sentData.clear();
+        feedBytes(TelnetConstants.IAC, TelnetConstants.WILL, TelnetConstants.TELOPT_TM);
+        boolean foundDoTm = false;
+        for (byte[] pkt : connection.sentData) {
+            if (pkt.length == 3 && (pkt[0] & 0xFF) == TelnetConstants.IAC &&
+                (pkt[1] & 0xFF) == TelnetConstants.DO && (pkt[2] & 0xFF) == TelnetConstants.TELOPT_TM) {
+                foundDoTm = true;
+            }
+        }
+        assertTrue(foundDoTm, "Expected IAC DO TELOPT_TM reply upon receiving IAC WILL TELOPT_TM");
+    }
+
+    @Test
+    public void testIACAYT() {
+        fsm.onConnected();
+        connection.sentData.clear();
+
+        // Host sends IAC AYT
+        feedBytes(TelnetConstants.IAC, TelnetConstants.AYT);
+        boolean foundNop = false;
+        for (byte[] pkt : connection.sentData) {
+            if (pkt.length == 2 && (pkt[0] & 0xFF) == TelnetConstants.IAC && (pkt[1] & 0xFF) == TelnetConstants.NOP) {
+                foundNop = true;
+            }
+        }
+        assertTrue(foundNop, "Expected IAC NOP acknowledgment for IAC AYT");
+    }
+
+    @Test
+    public void testTTypeCycling() {
+        fsm.onConnected();
+        connection.sentData.clear();
+
+        // Enable TTYPE
+        feedBytes(TelnetConstants.IAC, TelnetConstants.DO, TelnetConstants.TELOPT_TTYPE);
+
+        // First SEND request -> Expect configured type IBM-3279-4-E
+        feedBytes(TelnetConstants.IAC, TelnetConstants.SB, TelnetConstants.TELOPT_TTYPE,
+                  TelnetConstants.TELQUAL_SEND, TelnetConstants.IAC, TelnetConstants.SE);
+        byte[] lastPkt = connection.sentData.get(connection.sentData.size() - 1);
+        String resp1 = new String(lastPkt, 4, lastPkt.length - 6);
+        assertEquals("IBM-3279-4-E", resp1);
+
+        // Second SEND request -> Expect fallback IBM-3279-4
+        feedBytes(TelnetConstants.IAC, TelnetConstants.SB, TelnetConstants.TELOPT_TTYPE,
+                  TelnetConstants.TELQUAL_SEND, TelnetConstants.IAC, TelnetConstants.SE);
+        lastPkt = connection.sentData.get(connection.sentData.size() - 1);
+        String resp2 = new String(lastPkt, 4, lastPkt.length - 6);
+        assertEquals("IBM-3279-4", resp2);
+
+        // Third SEND request -> Expect monochrome fallback IBM-3278-4-E
+        feedBytes(TelnetConstants.IAC, TelnetConstants.SB, TelnetConstants.TELOPT_TTYPE,
+                  TelnetConstants.TELQUAL_SEND, TelnetConstants.IAC, TelnetConstants.SE);
+        lastPkt = connection.sentData.get(connection.sentData.size() - 1);
+        String resp3 = new String(lastPkt, 4, lastPkt.length - 6);
+        assertEquals("IBM-3278-4-E", resp3);
+    }
 }

lib3270j/src/test/java/org/lib3270j/tls/TlsConfigTest.java

@@ -31,7 +31,7 @@ public class TlsConfigTest {
         assertEquals(992, c1.getPort());
 
         // ssl: prefix with explicit port
-        ConnectionConfig c2 = ConnectionConfig.parseHostString("ssl:zos.local:2323", 0, TerminalModel.IBM_3279_2);
+        ConnectionConfig c2 = ConnectionConfig.parseHostString("ssl:zos.local:2323", 0, TerminalModel.IBM_3279_4);
         assertTrue(c2.isUseTls());
         assertEquals("zos.local", c2.getHost());
         assertEquals(2323, c2.getPort());