I wouldn't run a computer off the generator unless a UPS (Uninterruptible Power Supply) was also connected to the computer. While a generator is being used in a power outage, you'd typically be using one device, then turning it off and turning another one on. You might momentarily experience a low-volts situation (especially if the generator is a lower cost model) and that could cause a computer drama that you'd be better off without.

"The voltage was 121-122, and the frequency was between 62 and 63 Hz."

Fractionally higher should not cause a problem.

Most electronics runs on DC anyway, and the first thing after stepping the voltage down it is rectified.

Some supplies even rectify the line voltage and then use switching techniques to lower the voltage.

A slightly lower frequency can be more of an issue than slightly higher (at lower frequency transformers can saturate).

Be careful what UPS you use if you are trying to protect yourself from a generator's dips and power quality issues.

Only an 'always online' UPS provides much protection.

Most UPS units pass the power directly from the input to output (sometimes with some filtering) when the voltage is 'normal.'

An 'on line' UPS always creates DC, then inverts the DC to create the output.
They provide much better isolation, but of course cost more.