1. iChat is No Longer Available: First and foremost, iChat was discontinued by Apple in 2012. It's been replaced by Messages, which is now the default messaging app on macOS and iOS. This is likely the reason for the issue you're experiencing.
2. Handwriting Features are Limited in Messages: While Messages supports some text formatting, it doesn't have built-in handwriting recognition like iChat may have had. You would need a third-party app or external software to achieve handwriting input in Messages.
3. Compatibility Issues: Even if iChat had handwriting features, it's possible that they were dependent on specific hardware or operating systems. If your computer doesn't meet those requirements, it won't work.
Possible Solutions (If You're Using Messages):
* Third-Party Apps: Search for apps like "Pen to Text" or "Handwriting Recognizer" on the Mac App Store. These can capture your handwriting and convert it to text.
* External Software: There are also external software programs available like "MyScript Nebo" which offers more advanced handwriting recognition features.
To help me understand better, could you clarify the following:
* Are you actually using iChat, or is it Messages?
* What operating system are you using?
* Did you ever have handwriting input working in iChat before?
Providing more context will allow me to give you more tailored advice.