How to represent binary for differential and Manchester coding?

Question

I have some questions with solution provided from random material, but I can't understand well.

Question 1:

I tried to represent binary for each block according to description in the picture above, is this correct? (where you see "? 1 1 1 0 0 0 0 ?") in terms of location I placed and the value of binary.

And also for 2 of "?"'s I drew at the end of each side, what would be good value to be in there? (i simply put "?" mark because I do not know binary for those 2 blocks)

================= END of Q1 =================

Question 2:

Similar question as question 1. I tried to represent binary for each block according to description in the picture above, is this correct? (where you see "0 0 0 ? 1 1 1 1") in terms of location I placed and the value of binary.

And also for "?" I drew around the mid point, what would be good value to be in there? (i simply put ? because I do not know binary for that block)

================= END of Q2 =================

Here are original images without my drawing in case if you need them to answer above questions:

Answer 1

The signal is either at +1 or -1, except when there is no communication. Additional protocols/conventions are needed to detect starts and ends of messages. For Q1, the two extreme values have no real value, it can be a convention as "messages start with a rising or falling edge..."

For Q2, your ? is a 0. For the Manchester format exposed, a synchronization method or external clock is needed for determining the phase, else all 1's and 0's are inverted.

For example, with the old 10Mbps Ethernet, frames start with a known header (named "Preamble/Start Of Frame"). For the MIL-STD 1553 bus, frames begin with a high-low or low-high transition with lengthened bit times....