Currently I am on a 9 month over stay on a retirement visa.

I have been renewing the visa for 5 years now -- A lapse in memory and pain avoidance are my only excuses for the over stay.

What do I need to do to rectify this and get another retirement visa?

Do I have to exit country and apply for a non immigrant O?

If so, what is required (application form number, proof of income, photo, etc?

What sort of repercussion is there for the over stay as far as future visa applications are concerned?

Finally do they stamp my passport with over stay info? Is it stored in computer?

What if I get a new passport and apply fresh under a new number, will the over stay still show up?

Appreciation for your time and considered advice!

The Distressed

You will need to leave and get a new non-o visa paying the 20k baht fine on departure from the country.

There will be a stamp in your passport but that will not prevent you from getting a new extension of stay.

No special forms or financial proof will be needed to get a single entry non-o visa. You will fill out the embassy or consulates visa application form.

ieuueme

As above regarding the overstay.

If you want in future a "retirement visa" such a thing does not exist

The nearest you could get would be an O/A (long stay) visa which can only be obtained from a Thai Embassy/Official Consulate in your own country.