I just ran the ALL CODES diagnostic on my 1998 STS and came up with these:

AMP
U1255
U1064
U1128
U1016

IPC
B1652
B1983
U1301

SPM
U1301

Anyone know what these are or where I can get the information on them? Nothing seems to be wrong with the car, and no lights are on the dash telling me to do this, I was just curious what the code history was like.

Thank you!!!

You can go here to find out what your codes mean: http://myweb.accessus.net/~090/dtcobd2n.html#net

I looked them up for you and this is what they mean:
B1652 - Loss of Keep Alive Memory (KAM)
B1983 - Device Power Circuit Low
U1016 - Loss of Class 2 Communication with VCM
U1064 - Loss of Communications with DIM
U1128 - Loss of Communications with IRC
U1255 - Class 2 Communication Malfunction (Serial Data Line Malfunction)
U1301 - Class 2 Short to Battery

Also this is some info related to Code U1255: DTC U1000 or U1255 may set current or history, with or without other DTCs.

These DTCs set when the control module does not receive a message that it was expecting from another control module, and does not know which control module did not send the message.

If the DTC U1000 or U1255 is set in history with other DTCs set current or history, diagnose the other DTCs first.
If the DTC U1000 or U1255 is set current, this usually indicates a module that is currently not communicating or a configuration issue. For example, if the control module is configured for an option (i.e., OnStar, keyless entry, memory mirrors, etc.) that the vehicle does not have, it may expect to receive a message regarding this missing feature. This would usually occur due to the control module being recently replaced and incorrectly set up.
When the DTC U1000 or U1255 is current, the module that is not communicating may not even be listed on the Tech 2 on the Diagnostic Circuit Check /Class 2 Message Monitor list.
If the DTC U1000 or U1255 has set in history without other DTCs, replacing the control module that set the DTC is most likely NOT the solution. The module that has set the code is looking for an input from another module that is not communicating. Because the module did not receive an input that it is expecting to see, it sets a U1000 or U1255 which indicates there was a loss of communications. Look at the customer's concern (i.e., intermittent, erratic tachometer operation). This will probably be a better indication of the control module that is the source of the concern.

AMP (Amplifier)
U1255 - Class 2 Communication Malfunction (Serial Data Line Malfunction)
U1064 - Loss of Communications with DIM
U1128 - Loss of Communications with IRC
U1016 - Loss of Communications with PCM

IPC (Instrument Panel Control module)
B1652 - Loss of Keep Alive Memory (KAM)
B1983 - Device Power Circuit Low
U1301 - Class 2 Short to Battery

SPM (you sure its not SDM? (Inflatable Restraint Sensing and Diagnostic Module))
U1301 - Class 2 Short to Battery

Addison ii, you beat me to it! lol