|wp34s Integer Word Size versus 16C|
Message #1 Posted by Jake Schwartz on 5 May 2011, 3:29 p.m.
Since in the wp34S manual (and I'm looking at the version whose page-1 display indicates version 793), it says on page two: "...completely incorporating the functionality of the famous progrmmer's calculator HP16C...", I thought I'd run the machine through its paces with the examples from the 16C manual. On page 32 of the 16C manual is a "word size" example, where when starting with a 16-bit word size in 2's-compliment mode and decimal base, the number 32767 is entered. After changing the word size to 8, the number is displayed as "-1" and then after reverting the word size back to 16, the number is shown as "255 d", since the upper half of the original 16 bits was truncated (as mentioned in the note at the bottom of the page) when the word size was halved.
So on the wp34s, I set word size to 16, 2's compliment mode and BASE10 and entered 32767 and saw "32767 d" as expected; then changed the word size to 8 and saw "-1 d" as expected. However, after changing the word size back to 16, the number reverted back to "32767 d", implying that the value in the x register had not been truncated when the word size had been halved. Since 16C compatability is expressed in the manual, shouldn't the truncation be taking place?