I read that FMP8 would hold a billion characters. So you can assume that you will be able to hold a least that amount.
Thank you for posting.
Frinholp is correct. From Knowledge Base article #7541:
Maximum Text Field Size:
"Up to 1 billion characters per field per repetition (limited by available memory) with optional text style runs and paragraph runs. Index is based on the first 100 characters of each word or value."
I was able to get 268,435,456 characters into a test field but my system did not have enough memory for more. This is understandable considering that 1 billion characters is at least 1GB.
Thank you very much. That helps.