Re: Lost in free format conversion.

On 25 Jan 2013 03:05, whatt sson wrote:

<<SNIP>>in EBCDIC a byte representing a
character "1" is the same as a byte representing a zoned numeric 1,
which is hex F1. So MOVE works coincidentally, with alpha fields and
zoned numeric fields as long as the number is positive. The "F" in F1
indicates it's "unsigned", a "C" indicates it's positive and "D"
indicates it's negative. The "sign" in a zoned field is represented
in the last byte (least significant). That's why you get the letter
"O", which is hex D6, representing the digit 6 in a negative number.

FWiW: While that effectively describes the Binary Coded Decimal (BCD) for Zoned Decimal on the IBM Mainframe, the midrange chose to eliminate the concept of unsigned digits; choosing instead to have its preferred _positive_ as the hex digit "F" and its preferred _negative_ as the hex digit "D". The only consequence that I am aware of, is that the one-digit decimal number of zero is a /positive/ value represented by x'F0'. And while the 0xD and 0xF are preferred signs, all of the hex digits 0xA to 0xF are valid representation for a sign.