(snip regarding packed decimal) (someone wrote) >It isn't. Only specific values are allowed as a sign.
X'A' through X'F' >>Suffice to say that it was once proposed that the "Add Register" >>instruction code, X'1A', could be used as a positive packed >>decimal "1" I suppose that could be done to save one byte. >Perhaps in ASCII mode, which no longer exists. > Certainly not in EBCDIC mode. I just looked, and it is still in z/Architecture. X'1A', X'1C', X'1E', and X'1F' are positive one, (AR, MR, ALR, and SLR). X'1B', and X'1D' are negative one, (SR, DR). If one wanted a plus or minus two, (ADR, MDR, AWR, SWR), and (SDR, DDR) respectively. I suppose in the early S/360 days one byte might have mattered. -- glen ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
