The original Robocop movie trailer had music in it from the Terminator and both were Orion distributed as I recall, so I suspect that helped fuel speculation about the two meeting.
We later get the comic mini series and Genesis/SNES games.
In the comic, it was Murphy being linked to the machines that made him Robocop that would bring Skynet online. A resistance fighter time jumped to kill him, succeeded at first until Skynet's forces in the future located the source of the time disruption and quickly sent a squad back.
Robocop later learns how he will affect the future and tries to end himself but Terminators again appear and stop that and then merge him with the defense grid and corrupt it into SKYNET.
Could make for an interesting movie plot. Despite Ahnold's age, I would want him as the Terminator, just CGI de-age him like they did for Genisys and perhaps CGI de-age Peter Weller so that he can play Robocop again.
To be honest though, despite the original Robocop being a walking tank, I would state that the Terminator would win in fight between them if it came down to hand to hand combat.
1. Robocop is a TANK, not quite built for speed. Terminators are built to fight in the field, infiltrate and assassinate. They are strong and fast.
2. Robocop needs to recharge and rest at regular intervals. Per T2 an 800 like Ahnold can run for a century on his one power cell. T3 then expanded it to fusion power cells.
3. Terminators are cyborgs ONLY in that flesh covers the metal, they don't possess emotions like Robocop or humans would, they do not feel pain, pity or remorse and the will not stop EVER! Robocop however is more of a true Cyborg in that there is an organic brain and some other bits of his human body in that armor. Robocop also has some feeling and damage him enough and he seems to feel some painful feed back.
4. Terminators do not carry ray guns with them from the future due to how the time field works (easily worked around, coat a ray gun with flesh then tear the flesh off after you arrive in the past). They are limited to the firepower of the era, so is Robocop.
5. Robocop's body armor is probably not as tough as a Terminator 800's, however the Sarah Connor TV series did show that 50 caliber rounds and hi-ex rounds can fatally blast a Terminator. Also the first movie showed homemade plastique explosives can do the job too, but you need to get up close and personal with them. However such firepower would do the same to Robocop.
6. both have sensors and targeting systems but I will again give the edge to the Terminator due to being future tech and being 100% machine so it can likely process data faster then Robocop.
Conclusion: I have no doubt Robocop would put up a good fight but in the end the Terminator should be able to destroy him.
the 2014 Robocop would stand less of a chance. He has less armor but can move faster then the original could. Otherwise, the disadvantages would be the same.
What people seem to forget about RoboCop is that it was satire! The mistake is taking it at all seriously. I'd rather Terminator not be sullied.