It's possible that it did - simulate a pre-computer world to begin with, that is. Individuals grow up in the matrix, from infancy to adulthood. The created world has to reflect that - the simulation has to run forwards in time. It's also communal, each individual is born, and grows up in a world where they are mostly interacting with other human beings (albeit through an interface). Human parents, human teachers, human peers, human scientists and theorizers. The machines can't interfere too much - disbelief is a game ender, as the attempt to program a paradise shows, human minds will reject the world if it doesn't work as they believe it should.
What does that mean? The simulation had to be old. Old enough to accommodate generations. Old enough people had been rescued out of it for a long time. If there were resets at all they would be rare and dangerous - after all, if people can sense (as deja vu) minor resets and glitches, then their lives can't be rewritten in the middle - any major change in their world would trigger disbelief, and they would kill themselves trying to wake up. So the simulation could not possibly run less than a full lifetime. On the other hand, people's lives overlap, and the simulation is communal. It has to be not only old enough for any individual, but also their parents, and children. And resets have to be tricky, probably using fake generations to age the populations in and out so the machines aren't back to disbelief wiping out their power source.
The easiest answer, for the machines, would be to pick a time in history, and let it run forward. The longer the loop, the better (since it means fewer resets). "The peak of your civilization" might be a hundred years, or a thousand. And given a world full of people and time, things would probably progress similarly in the simulation as it did in the "real" history it was emulating. People causing conflicts, making problems, looking for solutions, and inventing. Humans invented computers, they can probably reinvent them as often as the simulation resets.
And the machines probably couldn't stop them. The might be able to nudge history a bit, either to follow the 'real' history, or try to move away from it, but their influence had to be minimal so as to not invoke the disbelief again. They probably can't make people not-invent things, or make the inventing not-work... so computers have to exist as long as people invent them, and they have to let it play out or summarily discard everyone to start over.