HSDPA supporting file larger than 2GB

assets/disk0/tvdos/HSDPADRV.SYS

@@ -117,8 +117,9 @@ for (let tapeIndex = 0; tapeIndex < 4; tapeIndex++) {
     
     // Get file size - for HSDPA tapes, we don't know the size ahead of time
     // So we return a very large number to indicate it's available
+    // Using Number.MAX_SAFE_INTEGER to support files >2GB
     driver.getFileLen = (fd) => {
-        return 0x7FFFFFFF // Return max positive 32-bit integer
+        return Number.MAX_SAFE_INTEGER // 2^53 - 1 (9007199254740991) - safe for JS arithmetic
     }
     
     // Sequential read from tape

assets/disk0/tvdos/bin/playtav.js

@@ -548,11 +548,20 @@ function tryReadNextTAVHeader() {
                         offsetBytes.push(seqread.readOneByte())
                     }
 
-                    element.offset = 0
-                    for (let j = 0; j < 6; j++) {
-                        element.offset |= (offsetBytes[j] << (j * 8))
+                    // Split into low 32 bits and high 16 bits
+                    let low32 = 0
+                    for (let j = 0; j < 4; j++) {
+                        low32 |= (offsetBytes[j] << (j * 8))
                     }
 
+                    let high16 = 0
+                    for (let j = 4; j < 6; j++) {
+                        high16 |= (offsetBytes[j] << ((j - 4) * 8))
+                    }
+
+                    // Combine using multiplication (avoids bitwise 32-bit limit)
+                    element.offset = (high16 * 0x100000000) + (low32 >>> 0)
+
                     serial.println(`Element ${i + 1}: ${element.name} -> offset ${element.offset} (internal)`)
                 } else {
                     serial.println(`Error: Unknown addressing mode: ${element.addressingMode}`)
@@ -585,6 +594,7 @@ function tryReadNextTAVHeader() {
 }
 
 let lastKey = 0
+let skipped = false
 
 // Playback loop - properly adapted from TEV with multi-file support
 try {
@@ -614,6 +624,7 @@ try {
                         akku = FRAME_TIME
                         akku2 = 0.0
                         audio.purgeQueue(0)
+                        skipped = true
                     }
                 }
                 else if (keyCode == 20 && cueElements.length > 0) { // Down arrow - next cue
@@ -627,6 +638,7 @@ try {
                         akku = FRAME_TIME
                         akku2 = 0.0
                         audio.purgeQueue(0)
+                        skipped = true
                     }
                 }
             }
@@ -652,6 +664,11 @@ try {
                     FRAME_TIME = 1.0 / header.fps
                     audio.purgeQueue(0)
                     currentFileIndex++
+                    if (skipped) {
+                        skipped = false
+                    } else {
+                        currentCueIndex++
+                    }
                     totalFilesProcessed++
 
                     console.log(`\nStarting file ${currentFileIndex}:`)
@@ -834,7 +851,6 @@ try {
                 notifHidden = true
             }
 
-
             con.color_pair(253, 0)
             let guiStatus = {
                 fps: header.fps,
@@ -845,8 +861,8 @@ try {
                 qCo: decoderDbgInfo.qCo,
                 qCg: decoderDbgInfo.qCg,
                 akku: akku2,
-                fileName: fullFilePathStr,
-                fileOrd: currentFileIndex,
+                fileName: (cueElements.length > 0) ? `${cueElements[currentCueIndex].name}` : fullFilePathStr,
+                fileOrd: (cueElements.length > 0) ? currentCueIndex+1 : currentFileIndex,
                 resolution: `${header.width}x${header.height}${(isInterlaced) ? 'i' : ''}`,
                 colourSpace: header.version % 2 == 0 ? "ICtCp" : "YCoCg",
                 currentStatus: 1

assets/disk0/tvdos/include/seqreadtape.mjs

@@ -203,7 +203,7 @@ function skip(n0) {
     let n = n0
     while (n > 0) {
         let skiplen = Math.min(n, 16777215)
-        serial.println(`skip ${skiplen}; remaining: ${n}`)
+//         serial.println(`skip ${skiplen}; remaining: ${n}`)
         hsdpaSkip(skiplen)
         n -= skiplen
     }
@@ -237,14 +237,23 @@ function isReady() {
 }
 
 function seek(position) {
+    if (position < 0) {
+        throw Error("seek: position must be non-negative")
+    }
+
     let relPos = position - readCount
-    if (position == 0) {
-        return
-    } else if (position > 0) {
-        skip(relPos)
+
+    if (relPos == 0) {
+        return  // Already at target position
+    } else if (relPos < 0) {
+        // Seeking backward - must rewind and skip forward
+        hsdpaRewind()  // This resets readCount to 0
+        if (position > 0) {
+            skip(position)
+        }
     } else {
-        hsdpaRewind()
-        skip(position)
+        // Seeking forward - skip the difference
+        skip(relPos)
     }
 }