Superboy didn't know his Kryptonian heritage during each four seasons of the Superboy TV Series. Except for the snippet of information that Clark received in the episodes "Rites of Passage" part 1 and 2 (he was informed he was from another planet) the show ended with only that information given and Superboy knew nothing about what planet he was from, who his parents were or who he was exactly. However, he did actually find out (and very briefly) that he was from Krypton and who his real parents were in a two-part, second season episode(s) titled "Abandon Earth" and "Escape to Earth". But because time was changed, Superboy lost that information in time itself.
It must be noted that these two episodes are one of the best storylines of the series. We also see some very good performances from Gerard and Stacy, as Lana and Superboy have some very critical moments. Superboy is led astray in the episode "Abandon Earth" and it appears that all of his questions about his heritage were about to be answed and by his real parents: father Jor-El and mother Lara.
Superboy, Jor-El (Vorok) and Lara (Mir) stop a bank robbery (left photo); Superboy is reunited with his parents who are really imposters (Rigth photo)
This two-part storyline in the episodes "Abandon Earth"/"Escape to Earth" has been criticized as being the best - and oddly, the worst of the Superboy series. Perhaps this is because Jor-El and Lara were not exactly who they claimed to be, but were imposters of Superboy's parents. The fans on message boards appear to be divided on it; they either love it, or they hate it. I, on the other hand, loved it! Indeed, this tale had many strong points. For one, we get to see Jor-El and Lara.
Vorok and Mir pretend to be Superboy's parents in "Abandon Earth".
For two, Lana discovers Clark's secret identity. She is angry at Clark at first and says, "We've known each other all our lives...and you didn't trust me." You can watch the scene of Lana's revelation below. The clip is up on youtube.
We also see Superboy's cave, his iconic hideway that we find in the old DC comic books of the Superboy titles (underneath the Kent farm).
In these two episdes we discover that Superboy had molded a secret cavern (a cave) to store away memorable artifacts attained through previous episodes, like the large crucifix used to defeat Byron in "Run Dracula Run". In the pre-crisis Superboy comic books, Superboy had a hideaway underneath the farm house and this is where he stored many things from many of his earlier adventures. The Superboy TV Series was truly paying homage to the Superboy DC comic books when it utilized the historical setting of the pre-crisis Superboy cave.
This dual episode storyline was also very original and had an unexpected out-come. Apparently, these two people were not his real parents, but grotesque aliens in true form; but they can emulate any species they choose. They pretended to be Superboy's parents and convince Superboy with a lie to go to Krypton with them so that they could lock him up in their inter-planetary space zoo.
Superboy eventually learns the truth. Andy dies. And Superboy learns that his real parents died when Krypton exploded. Last but not least, the fourth strong point is an obvious one-- Lana Lang and Superboy profess their love for one another and embrace in a passionate kiss before they fade away from time. This was undeniably one of the most poignant and heart-felt moments of the series. You can watch the scene of the memorable kiss disappearing from time on youtube. I have added it just below for your viewing pleasure.
The weak points are George Lazenby (who played Jor-El; in real life he was the one-time James Bond in 'On Her Majesty's Secret Service') and Britt Ekland (who played Lara and coincidently was a former Bond Girl, Mary Goodnight). Their performances were sterile and cold, not to mention over-the-top at times (maybe even corny). However, if we compare them to the John Bryne's version of Jor-El and Lara who were intially written as cold on the surface, then it makes sense. And they do have a good excuse; they weren't exactly the real Jor-El and Lara of Krypton. They were imposters posing as Superboy's parents. They ran a space zoo, and they wanted to collect Superboy as their specimen.
Their real names were Vorok and Mir, not Jor-El and Lara. They had taken the identities of Jor-El and Lara from Superboy's infant memories. Lana explained it in a nut-shell during the episode "Escape to Earth" when she said, "You two are really sick!" Jor-El and Lara arrived on Earth in a Doctor-Who-ish vehicle than began to destory landmarks and property to get Superboy's attention. Once they got his undivided attention, they told Superboy that he is from a planet called Krypton, the planet of his birth. They wanted Superboy to go back home with them, where he truly belonged.
Later of course, Superboy learns about Vorok and Mir's lie ...and that his real parents were really dead. Krypton had been destroyed, along with his parents. Earlier on in "Abandon Earth", Vorok had killed Andy McAllister (Clark's roomate) and Lana finds out Clark's true identity. The plot had thickened, but Superboy made the choice to turn back time and erase all the damage Vorok and Mir had done. Sadly, this meant that he couldn't keep the new knowledge he had acquired about Krypton (nor could Lana keep her revelation about Clark being Superboy). But in the long run, it was the right thing to do.
Time was changed--Andy never died and Vorok and Mir never started their space zoo. Lana and Superboy declared a deep love for one another just before they disappeared in time. Everything went back to normal but both Lana and Clark felt that something had happened at the end, but couldn't quite put their finger on it. "Escape to Earth" ended on nice touch.
"Abandon Earth"/"Escape to Earth" are one of the best episodes of the series, and clearly demonstrates how having a lack of heritage about Krypton brought sympathy to the Superboy character.
NOTE: In the third season episode called "Mindscape" we actually do see (rather vaguely) and hear the voice of Jor-El when Superboy has a near-death experience. Superboy fights off an alien who is sucking his life-force and Jor-El tells Superboy that it is not yet his time to die. Superboy doesn't learn anything about his heritage, but he does discover he has a purpose.