# Finding op amp input and output range from datasheet

I have basic knowledge about op amps and am trying to build a non-inverting amplifier. I build the circuit below using $V_{CC} = 12V$ and a salvaged dual-package op amp (BA15218N) from an old radio, in order to test if they work correctly (desoldering them was not my best work).

But I noticed that $V_{out}=V_{in}$ was not always true. With $V_{in}$ dropping below about $1.4V$, $V_{out}$ quickly increases until it reaches nearly $V_{CC}$ potential at $V_{in} \approx 1.2V$.

I found out, that operating these amplifiers near their supply voltage is generally not a good idea/possible, but nowhere was this extreme behaviour mentioned in any tutorial or datasheet. I also read the datasheet of this op amp multiple times to find the voltage range of the input and output pins, but to the best of my knowledge they seem to be missing.

## Questions

1. Is any op amp working as intended when $V_{in} \approx 1.2V$, $V_{out} \approx 12V$ with gain $G=1$, or is my unit defective?
2. How can one determine the stable operating range of a specific op amp from the datasheet?