i have a stock that was purchased years ago that is worthless and i would like to abandon it for a write off or loss

If the stock is worthless, you should be able to report your complete investment in the stock.  Worthless stock includes abandoned stock, permanently surrendered for no consideration.

Enter a worthless stock like any stock sale but with a sales price of zero and the word worthless in its description. Enter the correct cost or basis, date acquired, and December 31 as the date sold.

See IRS Publication 550 Investment Income and Expenses, page 54.

In TurboTax Premier Online, follow these steps.       

1. Down the left side of the screen, click Federal.
2. Down the left side of the screen, click Wages & Income.
3. Click the down arrow to the right of Investments and Savings.
4. Click to the right of Stocks, Cryptocurrency, Mutual Funds, Bonds, Other (1099-B).
5. Click Add investments.
6. On the Let's import your tax info screen, select Enter a different way.
7. On the OK, let's start with one investment type screen, select Stocks, Bonds, Mutual Funds, then Continue.
8. At the screen Which bank or brokerage, enter the information.  Click Continue.
9. Do these sales include any employee stock, enter No.
10. Do you have more than three sales, enter No.
11. Do these sales include any other types of investments, enter No.
12. Did you buy every investment listed, enter Yes.  Continue.
13. On the screen Now, choose how to enter your sales, select One by one.  Select Continue.
14. At the screen Look for your sales on your 1099-B, select Continue.
15. You will now be able to enter $0 total proceeds (sales) and your cost basis, along with the sales category.  Select Continue.
16. At the screen Let us know if any of these situations apply to this sale, select This was a worthless security.  Select Continue.
17. At the screen Review your sales, select Add another sale as necessary.
18. When completed, close the record and click Continue.