Seiko's early quartzes can be downright intimidating, what do all these numbers and letters mean? Well, after some years of doing my research I can finally say with confidence what's what. 
As of 1971 The '38' movements were Seiko's first widely available quartz movements, but first was the 1969 Seiko Quartz Astron (100 or so made) representing a groundbreaking technological breakthrough. 

[attachment=2008]

The watch’s tuning-fork-shaped quartz oscillator gave the Astron’s movement, Calib

[attachment=4940]

[attachment=5092][attachment=5093][attachment=5094][attachment=5095][attachment=5096][attachment=5097][attachment=5098][attachment=5099][attachment=5100]