2001 S10 pickup radio unlock code.

Maybe this will help, found online:
http://autoforum.classifieds1000.com/Chevrolet-S10_Blazer/208607-radio_unlock_code
".... Call a GM dealer. They will instruct you how to extract codes from your locked radio. Give them the codes you retrieved from your radio. They will call a special number at Delco radio to get you an unlock code. They (the GM dealer parts or service person) will give you the unlock code, and the procedure for your specific radio. Follow the instructions, and you're radio is working!Now, here is the big tip on this- Some dealers will get the code for you NO CHARGE. Others will charge you around 50 bucks. It depends on the dealership, and how much you deal with your local dealership. I worked in a GM parts department, and I had NEVER charged one of my regular customers for the code to unlock their radio.
Also, no dealer will unlock a radio, unless you can show ownership of your vehicle. It's just like getting new keys form VIN# for your vehicle, from a dealer, it's a legal issue."

ALSO found:
http://www.thechevytruckclub.com/forum/showthread.php?t=2534
"... Try this, it worked for my 1998 Sunfire and a 1975 Monte Carlo.
Press & hold the 2 & 3 buttons @ the same time for about 10 seconds; a 2 or 3 digit code will appear, write this # down,press & hold the am/fm button for about 10 seconds: another code will appear, write this # down, then call 1-800-537-5140 and enter 202108 followed by the # key, then enter the #'s that you wrote down from your radio followed by the * key. The call will give you a 3 or 4 digit override code. Write this code # down so you have it if you ever need it again. Enter this # into your radio following the instructions in your owners manual. If you get an override code that starts with 0, you drop the 0 when entering the code into your radio.
If you don't have an owners manual, try this, press & hold the hour button until the first 2 digits of your code come up, then press & hold the minute button until the last 2 digits show. Then press the am/fm button. This should reset your stereo. It did mine...."