alt Hacker NewsI was thinking, in a world without DRAM, cobalt-infused magnetic tape (like that used for VHS and ferricobalt cassettes) or metal particle tape, digital sound recording would still be possible using 1960s black-and-white VTRs that took ferric oxide tape not dissimilar to those used for analog multitrack recording.
In terms of physical media:
For 1/8" cassette tape, KCS appeared in 1975 but the tape itself was in use 20+ years prior: https://en.wikipedia.org/wiki/Kansas_City_standard
½" consumer tape of Betamax and VHS didn't arrive until the same year.
¼" QIC DC300 appeared ~1972 but was largely inaccessible to hobbyists and home users until around 1995/1996 with QIC-40 and Travan.
There were also home 1/4" reel-to-reel home audio systems from roughly mid '50's onward.