It would have come from the factory w/R12, someone could have convereted it to r134. If that happened the low pressure line (larger line) should have a blue cap on it. The schrader valve would be appx 3/8" across.
A properly converted system will have the R134A quick-connect fittings on the service ports. If it has screw-on fittings that look like a tire valve, it is either still running R12 or was converted improperly, without installing proper service adapters.
Also, if it blows ice cold in 100 degree weather, its R12!
Should be a label on the silver A/C canister on the passenger side firewall under the hood... many times, if converted over to r134a, the garage that did it puts a sticker on the the canister and/or cowl to state the conversion.