Joe, I believe Fat Air is correct, if you accidentally deleted your sat positions they are gone for good. I have read many of Mr. Air's posts and am pretty sure he has forgotten more about this stuff than I will ever know.
If you need an electronic copy of the 1820 Users Manual please private message me your email address and I will shoot it to you. I tried to upload it to our Manuals Section but couldn't make it happen. Or if you would like I could email it to Iceberg and he could post it here.
There is a manual for the Toshiba 1420 in the Manuals section, many features are similar. If you look on page 47 of that one they describe how to do a satellite position realignment, but if those positions have been deleted I don't think that will help.
I am still using a Toshiba 1820 to move a 10' BUD/Polarotor setup, and it works great.
It may be going into "semi-retirement" once I get my 12 footer up and going but it's been a good unit, built like a tank and hasn't missed a beat for almost 20 years. If it ever croaks I will probably retask it as a weapon, or to drive fence posts!
Good luck and welcome!