Have you ever heard of a "sound camera"? In the early 1960's, when portable (battery powered) tape recorders were appearing on the market, the idea that you could record sounds found at home/office/travel locations was popularized. Submitted for your approval is the Sanyo Micro-Pack 35 tape recorder, which came to market along with the Philips Compact Cassette. I actually used a Channel Master version (I think) and found it ultimately underwhelming for recording TV audio with the supplied microphone. But "Techmoan" has nice things to say about this early solution to the complexity of reel-to-reel tape recorders. ("Mission: Impossible" on TV featured a tiny (tinny?) tape recorder to brief "Mr. Briggs" on the team's next spy caper!)