Swap HDs from Series 1 to Series 2 Tivos

I have a tivo 1 gathering dust,
and a series 2 that just died.

The tivo 2 has lifetime so I keep
it for just basic cable.

Can I pluck out the series 1 hd
and put it in the series 2?

These are both tivo brand.
Both are old from back in the day!

Thanks