Canon EOS 620 - 650 camera manual
Quartz Date Back E Technical Back E / Interface Unit TB / Keyboard Unit E
The Quartz Date Back E is a fully automatic data back which imprints data on the film.
1.Auto date up through the year 2029. (automatic compensation for leap years and long/ short months)
2.Auto digital clock mode (Day/Hour/Minutes) with 24 hour display.
3.Arbitrary
4.Frame counter number from Fc 0001 through 9999.
As the name "Technical" suggests, the Technical Back E not only imprints the data and arbitrary comments (up to 30 digits) on film but memorizes shooting data such as shutter speed, aperture value, lens focal length and film speed.