Given that the word length is a multiple of 4 bits, it is natural to group the data into groups of 4 bits, just as on 36 bit machines it was natural to group bits into groups of 3 and use octal notation. Add in the hexadecimal floating point and hex seems even more natural. The values 10 base 10 and 0A base 16 are the same, as is 1010 base 2, and which you use is purely a matter of convention and convenience.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List [[email protected]] on behalf of Charles Mills [[email protected]] Sent: Wednesday, June 7, 2023 4:08 PM To: [email protected] Subject: Re: Shower thought Dave, no offense was intended. Yes, I totally understood your meaning. The mis-use of the term hexadecimal to mean vaguely "some value, possibly not a printable character" is a personal bugaboo of mine. The IBM doc does it: talking about specifying a word as containing "a hexadecimal value" when what they mean is a binary value. Specifying a hexadecimal value would mean specifying (character) 000A when what you meant was a binary value equal to decimal 10. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Dave Clark Sent: Wednesday, June 7, 2023 11:17 AM To: [email protected] Subject: Re: Shower thought "IBM Mainframe Assembler List" <[email protected]> wrote on 06/07/2023 02:02:58 PM: > No! Not a hexadecimal comparison. If it were, 11 would compare higher than > AA at least in an EBCDIC environment. You're too literal. I didn't say the comparison was on the hexadecimal *value*. What I mean by a hexadecimal comparison (and I've seen it used this way elsewhere) is that it is a bit-by-bit, left-to-right unsigned comparison. Proof that you understood that, but chose to object anyway, is that you *didn't* object to it being called a *character* comparison -- even though I explicitly said that first. After all, it is not truly a *character* comparison, either. It is a bit-by-bit, left-to-right unsigned comparison and I've seen that called both a character comparison and a hexadecimal comparison because it is shorter to say and it is generally understood correctly even if the actual wording is nonsensical. I'll not argue it further.
