Clare-Pendar Series S880
Clare-Pendar Series S880 is the low-profile alternative to S820 series. It is almost identical internally and externally to the European-made SFL, SIL and SGL counterparts.
YouTube video Cherry KFN3 keyboard review (Cherry solid-state capacitive, shamrock-type) depicts an excerpt from Electronic Design 11 from the 24th of May 1979, in which Series S880 is given as “just introduced” by “C.P. Clare Co.” which gives some indication of their age.
(The video does not indicate how to access these back-issues of Electronic Design magazine, but the screenshot suggests that it is not from the Internet Archive, where only a few issues are posted.)
- Lone S88210 (SPST NO alternate action) in the Harris EKA-8970 keyboard made by TEC; it is dated 7939, and seemingly unbranded.
- S880 entry, Deskthority wiki (all my prior notes)