Early electronic clock chimes are a barely researched fascinating topic. Unlike synths, they are still rated trash and no serious part of clock history. E.g. the "Kienzle Variogong" chime synthesizes only does "bim bam" from a crazy amount of logic ICs and mixing its 2 bell notes from each 4 squarewaves (with tuning trimmers) and analogue decay envelope (i.e. having 8 trimmers and 8 capacitors only to play 2 bells). A later chime was "Junghans Quattro-phon", which already was single-chip digital hardware, but it has 4 polyphonic clock sounds (2 chip variants exists) made from layered squarewave tones and the quartz clockwork still had a big brown design case with stylish knobs of those the designer certainly was proud of, while most later quartz movements became boring black cheap plastic things intended to be hidden and hopefully never to be looked at again.
If anybody is interested in emulating the first digital clock chimes, check out Kienzle Variogong (patent US4270200, DE000002753733A1, will likely need netlist) and Junghans Quattro-phon (patents US4271495, DE000002850286A1, single-chip likely needs decapping). Clocks with the latter were also sold under a couple of different brands, but the the big brown quartz movement with big knobs (Junghans W771, W772, Hermle 1217) is easy to identify.
