diff --git a/demo/client.ts b/demo/client.ts
index 02b9f7be..ceb3fab1 100644
--- a/demo/client.ts
+++ b/demo/client.ts
@@ -1266,10 +1266,13 @@ function addVtButtons(): void {
 
     const element = document.createElement('button');
     element.textContent = name;
-    writeCsi.split('');
-    const prefix = writeCsi.length === 2 ? writeCsi[0] : '';
-    const suffix = writeCsi[writeCsi.length - 1];
-    element.addEventListener(`click`, () => term.write(csi(`${prefix}${inputs.map(e => e.value).join(';')}${suffix}`)));
+    const writeCsiSplit = writeCsi.split('|');
+    const prefix = writeCsiSplit.length === 2 ? writeCsiSplit[0] : '';
+    const suffix = writeCsiSplit[writeCsiSplit.length - 1];
+    element.addEventListener(`click`, () => {
+      debugger;
+      term.write(csi(`${prefix}${inputs.map(e => e.value).join(';')}${suffix}`));
+    });
 
     const desc = document.createElement('span');
     desc.textContent = description;
@@ -1281,22 +1284,23 @@ function addVtButtons(): void {
   }
   const vtFragment = document.createDocumentFragment();
   const buttonSpecs: { [key: string]: { label: string, description: string, paramCount?: number }} = {
-    A:    { label: 'CUU ↑',  description: 'Cursor Up Ps Times' },
-    B:    { label: 'CUD ↓',  description: 'Cursor Down Ps Times' },
-    C:    { label: 'CUF →',  description: 'Cursor Forward Ps Times' },
-    D:    { label: 'CUB ←',  description: 'Cursor Backward Ps Times' },
-    E:    { label: 'CNL',    description: 'Cursor Next Line Ps Times' },
-    F:    { label: 'CPL',    description: 'Cursor Preceding Line Ps Times' },
-    G:    { label: 'CHA',    description: 'Cursor Character Absolute' },
-    H:    { label: 'CUP',    description: 'Cursor Position [row;column]', paramCount: 2 },
-    I:    { label: 'CHT',    description: 'Cursor Forward Tabulation Ps tab stops' },
-    J:    { label: 'ED',     description: 'Erase in Display' },
-    '?J': { label: 'DECSED', description: 'Erase in Display' },
-    K:    { label: 'EL',     description: 'Erase in Line' },
-    '?K': { label: 'DECSEL', description: 'Erase in Line' },
-    L:    { label: 'IL',     description: 'Insert Ps Line(s)' },
-    M:    { label: 'DL',     description: 'Delete Ps Line(s)' },
-    P:    { label: 'DCH',    description: 'Delete Ps Character(s)' }
+    A:     { label: 'CUU ↑',    description: 'Cursor Up Ps Times' },
+    B:     { label: 'CUD ↓',    description: 'Cursor Down Ps Times' },
+    C:     { label: 'CUF →',    description: 'Cursor Forward Ps Times' },
+    D:     { label: 'CUB ←',    description: 'Cursor Backward Ps Times' },
+    E:     { label: 'CNL',      description: 'Cursor Next Line Ps Times' },
+    F:     { label: 'CPL',      description: 'Cursor Preceding Line Ps Times' },
+    G:     { label: 'CHA',      description: 'Cursor Character Absolute' },
+    H:     { label: 'CUP',      description: 'Cursor Position [row;column]', paramCount: 2 },
+    I:     { label: 'CHT',      description: 'Cursor Forward Tabulation Ps tab stops' },
+    J:     { label: 'ED',       description: 'Erase in Display' },
+    '?|J': { label: 'DECSED',   description: 'Erase in Display' },
+    K:     { label: 'EL',       description: 'Erase in Line' },
+    '?|K': { label: 'DECSEL',   description: 'Erase in Line' },
+    L:     { label: 'IL',       description: 'Insert Ps Line(s)' },
+    M:     { label: 'DL',       description: 'Delete Ps Line(s)' },
+    P:     { label: 'DCH',      description: 'Delete Ps Character(s)' },
+    ' q':  { label: 'DECSCUSR', description: 'Set Cursor Style', paramCount: 1 }
   };
   for (const s of Object.keys(buttonSpecs)) {
     const spec = buttonSpecs[s];