@ Chris
The TAS could have been the actual velocity thru the airmass, and we didn't have the computer use system altitude to calculate the CAS. That was just my own "invention" if we wanted to do it. The winds were easy, and we could display them on our nav panel. Our nav system was better than any other plane for another ten years or so. We had a super inertial, a doppler and a nav computer borrowed from the Apollo lunar landing module - an IBM PI 3, or close to it. So we had about 5 nav modes until it came down to the primitive methods we had all learned. We could even align the INS using the doppler, then get a nav fix for navigation and press on.
BTW, I flew from Hawaii to Guam in our "airmass mode" using predicted winds aloft and only my TAS from the air data computer and attitude/heading from the basic gauges. You know, the way we used to do back when the earth was still cooling and had no doppler or computers or.... I did it because I was in a flight alongside a tanker and the weather was supposed to be good. Besides, I had an ADF for homing if I got lost ( thinking of Amelia,,,,,)
I was about 15 miles off when getting to Guam. Not too shabby. Island was easy to spot due to the clouds above, so I would have made it without help.