Hi It doesn't look like it has enough on it to be a RS-232 converter but it could be a 20 to 60 mil converter. You might look at the circuit layout around the thansistors labeled Q1 to Q4. Tracing this part out will most likely figure out what the intent is. It looks like it does replace some of the power supply sections of a ASR33 so that would explain the look of a power supply. You can power the unit up and look at the voltages on the DB25. I tend to agree that missing both pin 1 and pin 7 would indicate that it wasn't a RS232. Dwight