Did a quick search for OS8.1 pricing and found a very wide range!

Apple software is still selling OS8.1 v 2.1 w manual for ~ $120 w taxes. Ebay very low prices but no mention of what version and if
if contains the manual. Most just said new in box or full version new in retail box. Others said 8.1 upgrade CD only-full install of 8.1 . Absolutely confusing!

Is the manual useful or is it better to get an OS 8.1 text?

Is there any significant difference between the 8.1 versions? Had only been recommended to get the FAT or Full version.

Thanks!

Contact SunRem.com and see what they would recommend for your machine.

Then call macresq.com or owcomputing.com and buy it from them. Or mediaguide.com . They're all good folks. Or SunRem.com if they're cheap enough (they're good people, too, just outrageously high on some things).

You want the OEM version, the manual isn't necessary. If you're installing it on a Quadra or Centris, then make sure the one you buy will work with that (I think they all will, except those which shipped with specific Apple computers). The retail version will definitely work with whatever you have.

It should sell for less than $40, too.