1) @djsfantasi and I resolved the misunderstanding. What I meant was the binary byte is read the same direction whether the ordering of bytes is big or little endian. The endian does not change bit or nibble order. So whether the string is in BCD or hexadecimal it doesn't matter. He obviously thought I meant bit order per se was a palindrome, and I was not clear on that. No need for a dissertation on it.
2) With regard to FIFO and LIFO, it is quite easy to write enhanced midrange PIC code to handle byte strings of several hundred bytes. Your persistence in demanding to know ahead of time the length of the string doesn't seem to have helped the TS one bit. He has not responded in 36 hours. All one would need to know with the MCU I described is that the string is less than, say 1024 bytes, and has a terminator that can be identified.
2) With regard to FIFO and LIFO, it is quite easy to write enhanced midrange PIC code to handle byte strings of several hundred bytes. Your persistence in demanding to know ahead of time the length of the string doesn't seem to have helped the TS one bit. He has not responded in 36 hours. All one would need to know with the MCU I described is that the string is less than, say 1024 bytes, and has a terminator that can be identified.