I can't imagine that overclocking was already a thing back in the 70s. So just because Intel specified a narrow operating range doesn't mean that it is guaranteed not to work outside that envelope.
I can imagine Intel to just have specified a narrow operating range where the device is guaranteed to work reliably within the specified voltage/power envelope. We might be surprised to see higher clock speeds if we play with the supply voltage for example.
I can imagine Intel to just have specified a narrow operating range where the device is guaranteed to work reliably within the specified voltage/power envelope. We might be surprised to see higher clock speeds if we play with the supply voltage for example.