When AFM Stereo was introduced to 8-mm video?

[DVtyro]

Does anyone know the timeline regarding AFM Mono, AFM Stereo and PCM on 8-mm video? AFAIK, AFM Mono was from the beginning. PCM was introduced in 1986 if I am not mistaken. When AFM Stereo was introduced?

This article from 1986 reads:

“The quality of the hardware was the determining factor,” explained Tim Clott, Paramount Home Video senior vice president and general manager. “We didn’t want to put our films out on systems that didn’t play them back properly. The picture quality of 8mm has improved greatly over the last year or two. It’s now comparable to the best half-inch (VHS and Beta) systems. Now there’s good-quality digital sound too. The earlier version of 8mm didn’t have digital sound.”

To me, the only benefit of PCM Audio vs AFM on 8-mm is that PCM can be re-dubbed without disturbing the video, which is not a factor for a pre-recorded movie. Regarding audio quality, 8-bit @ 32 kHz sampling rate is worse than 20-20K of AFM Stereo. This leads me to the conclusion that the second channel was added to AFM after PCM was introduced. Am I wrong? If someone knows for sure, I would appreciate the info. Even better, if you have a link!

And while I am at it, were 120-minute tapes available from the very beginning in 1984, or were introduced later? They sure were available in 1986.

Am I correct in my thinking that 8-mm was originally designed as a camcorder format only, hence 60-min tapes and AFM Mono, but after Sony realized that Beta was going to lose to VHS, Sony decided to push 8-mm as a general usage format to replace Beta. 150-min tapes became available. There were even 180-minute tapes, although I've never held one in my hands.