It appears to be a custom version of Chicago, one of Apple's former system fonts (Mac OS 8 and 9). It is not freely available anywhere.

It looks like Handel Gothic.

I scanned this sample from an Atari BASIC tutorial book published in 1982. The font is similar to Optima, but the capital W is narrower and the capital G has an added horizontal stroke. Can anyone identify this text font?

Try Slicker, a freeware version of Handel Gothic, from The Price Is Right Font Archive.

Edit: link removed (commercial fonts for free)