diff --git a/tools/cheat-builder/explain.ts b/tools/cheat-builder/explain.ts
new file mode 100644
index 0000000..130fb28
--- /dev/null
+++ b/tools/cheat-builder/explain.ts
@@ -0,0 +1,128 @@
+
+const fs = require('fs');
+
+const align = (t, b) => t % b == 0 ? t : t + b - t % b;
+
+const getSerial = (buffer: Buffer, offset: number, base1: number, base2: number) => {
+    if( offset >= base2 ){
+        let n = Math.floor( (offset-base2) / 8 );
+        let c = (base1-8) / 3;
+        for(let i=0; i < c; ++i ){
+            let a = buffer.readUInt16LE(base1 + i*2);
+            let b = buffer.readUInt16LE(base1 + i*2 + 2);
+            if( a <= n && n < b ){
+                let start = 8 + i * 3;
+                let str = String.fromCharCode( buffer[start], buffer[start+1], buffer[start+2] );
+                return [str, i];
+            }
+        }
+        return ["????", -1];
+    } else if( offset >= base1 && offset < base2 - 2 ) {
+        let n = offset - base1;
+        n = Math.floor( n/2 );
+        let start = 8 + n * 3;
+        let str = String.fromCharCode( buffer[start], buffer[start+1], buffer[start+2] );
+        return [str, n];
+    }
+    else return ["????", -1];
+}
+
+const describe = (buffer: Buffer, offset: number) => {
+    console.info(`error at ${offset}`);
+    let n = buffer.readUInt16LE(4);
+    let serialbase = 8;
+    let offsetbase = serialbase + 3*n;
+    let cheatbase = offsetbase + 2 * (n+1);
+    let cheatcnt = buffer.readUInt16LE(cheatbase-2);
+    let expandbase = align( cheatbase + 8 * cheatcnt, 32 );
+    let serial = "????", entry = -1;
+    if( offset >= offsetbase ) [serial, entry] = getSerial(buffer, offset, offsetbase, cheatbase);
+
+    console.debug("is it right? %d - %d - %d - %d", serialbase, offsetbase, cheatbase, align(expandbase, 32));
+    if( offset < serialbase ){  // 属于HEAD数据
+        if( offset < 4){
+            console.log("INSIDE MAGIC NUMBER");
+            console.log("ACL?");
+            console.log(new Array(offset).fill(" ").join("")+"^");
+        }
+        else if( offset < 6 ){
+            console.log("INSIDE SERIAL LENGTH");
+            console.log(n.toString(16).padStart(4, '0'));
+            console.log(new Array(5 - offset).fill("  ").join("")+" ^");
+        }
+        else {
+            console.log("INSIDE MAX CHEAT PARAGRAPH");
+            n = buffer.readUInt16LE(6);
+            console.log(n.toString(16).padStart(4, '0'));
+            console.log(new Array(7 - offset).fill("  ").join("")+" ^");
+        }
+    }
+    else if( offset < offsetbase ){
+        let start = serialbase + Math.floor( (offset-serialbase)/3  ) * 3;
+        console.log("INSITDE SERIAL COLLECTIONS", "index =", Math.floor(  (offset-serialbase)/3  ));
+        console.log( String.fromCharCode( buffer[start], buffer[start+1], buffer[start+2] ) );
+        console.log( new Array(offset-start).fill(" ").join("")+"^" );
+    }
+    else if( offset < cheatbase ){
+        let start = offsetbase + Math.floor( (offset-offsetbase)/2  ) * 2;
+        console.log("INSITDE SERIAL EXTENSIONS", "index =", Math.floor(  (offset-offsetbase)/2  ), "serial(3) =", serial);
+        if( offset > offsetbase+1 ){
+            n = buffer.readUInt16LE(start-2);
+            console.log(n.toString(16).padStart(4, "0"), "   <<<  ", getSerial(buffer, offset-2, offsetbase, cheatbase)[0]);
+        }
+        n = buffer.readUInt16LE(start);
+        console.log(n.toString(16).padStart(4, '0') );
+        console.log(new Array(offset - start).fill("  ").join("")+" ^");
+    }
+    else if( offset < expandbase ){
+        if( offset < cheatbase + cheatcnt * 8 ){
+            let start = cheatbase + Math.floor( (offset-cheatbase) / 8 ) * 8;
+            let entstart = buffer.readUInt16LE( offsetbase + entry*2 ), h, l;
+            entstart = cheatbase + entstart * 8;
+            console.log("INSITDE CHEAT SEGMENTS", "index =", Math.floor(  (offset-cheatbase)/8  ), "serial(3) =", serial);
+            while( entstart < start ){
+                h = buffer.readUInt32LE(entstart);
+                l = buffer.readUInt32LE(entstart+4);
+                console.log(h.toString(16).padStart(8, '0') + "  " + l.toString(16).padStart(8, '0'));
+                entstart += 8;
+            }
+            h = buffer.readUInt32LE(start);
+            l = buffer.readUInt32LE(start+4);
+            console.log(h.toString(16).padStart(8, '0') + "  " + l.toString(16).padStart(8, '0'));
+            if( offset - start < 4 ){
+                console.log(new Array(3 - (offset - start)).fill("  ").join("")+" ^");
+            }
+            else console.log(new Array(12 - (offset - start)).fill("  ").join("")+" ^");
+        }
+        else {
+            console.log("INSITDE CHEAT SEGMENTS PADDING" );
+        }
+    }
+    else if( offset < buffer.length ){
+        console.log("INSIDE CHEAT BINARY");
+        // 1 index from cheatbase
+        // 2 index from offsetbase
+        // 3 get offset for cheat bin
+        // 4 show for entry size/entry record/string table/index table/code table
+    }
+    else {
+        console.error("INVALID POSITION AT %d", offset);
+    }
+}
+
+const main = (argv: string[]) => {
+    if( argv.length < 2 ) {
+        console.info("Usage: explain <file1> <file2>");
+        return;
+    }
+    const first: Buffer = fs.readFileSync(argv[0]);
+    const second: Buffer = fs.readFileSync(argv[1]);
+
+    let diff = 0;
+    for(; first[diff] === second[diff]; diff++);
+    describe(first,diff);
+    console.log("------------------");
+    describe(second,diff);
+}
+
+main( process.argv.slice(2) );
diff --git a/tools/cheat-builder/make-acl.rs b/tools/cheat-builder/make-acl.rs
index f565e59..4d2e3e3 100644
--- a/tools/cheat-builder/make-acl.rs
+++ b/tools/cheat-builder/make-acl.rs
@@ -613,6 +613,7 @@ fn loadlist() -> Vec<(String,String)> {
     .expect("JSON was not well-formatted");
 
   if let Value::Object(map) = json_data {
+    retval.reverse( map.len() );
     for (key, value) in map.iter() {
       if let Value::String(serial) = value {
         if serial != "????" {
@@ -782,4 +783,4 @@ impl<'a> Iterator for Utf8CharIter<'a> {
 }
 
 impl<'a> FusedIterator for Utf8CharIter<'a> {}
-*/
\ No newline at end of file
+*/