Books

I remember, once upon a time, hunting down books on the various hunks of military equipment in Twilight: 2000.

Some of those books got very expensive because the information was very niche.

And much of the information on Soviet stuff was just flat wrong.  But we had no way of knowing at the time.

Today, nearly everything I need for T2K levels of accuracy is readily available on the internet.

It's glorious in its way.

I had no idea, for example, that Czechslovakia never adopted the AK or converted to 5.45.  That Poland made their own 5.45 AKM instead of just paying the licensing fees (like East Germany did).

Detailed information about armor and gun performance was simply not available from an unclassified source.

The future is kinda neat sometimes.