I'm not sure why I bother to post to this list, since apparently people don't bother to read my messages. page 2-15: "This set of five instructions allows the programmer to pack or unpack bytes of any length from anywhere within a word. ... The byte manipulation instructions have the standard memory reference format, but the effective address E is used to retrieve a pointer, which is used in turn to locate the byte ... The pointer has the format 0 5 6 11 12 13 14 17 18 35 P S I X Y where S is the size of the byte as a number of bits, and P as its position as the number of bits remaining at the right of the byte in the word ... To facilitate processing a series of bytes, several of the byte instructions increment the pointer, ie modify it so that it points to the next byte position in a set of memory locations. Bytes are processed from left to right in a word, so incrementing merely replaces the current value of P by P-S, unless there is insufficient space in the present location [i.e. 'word' - JNC] for another byte of the specified size (P-S < 0). In this case Y is increased by one to point at the next consecutive location, and P is set to 36 - S to point to the first byte at the left in the new location." Now imagine implementing all that in FLIP CHIPs which held transistors (this is before ICs)! Anyway, like I said, at least ITS (of the PDP-10 OS's) used this to store ASCII in words which contain five 7-bit _bytes_. I don't know if TENEX did. Huh? Which machine used the term 'octet'? Like I said, we adapted and used the term 'octet' in TCP/IP documentation (and that's definite - go check out historical documents, e.g. RFC-675 from 1974) because 'byte' was at the time ambiguous - the majority of machines on the ARPANET at that point were PDP-10's (see above). Interestingly, I see it's not defined in that document (or in the earlier RFC-635), so it must have already been in use for an 8-bit quantity? Doing a little research, there is a claim that Bob Bemer independently invented the term in 1965/66. Perhaps someone subconciously remembered his proposal, and that's the ultimate source? The term is also long used in chemistry and music, of course, so perhaps that's where it came from. Noel