HP 35S drop key? - Hewlett Packard

This is a discussion on HP 35S drop key? - Hewlett Packard ; I just got my 35S and so far like it very much. I'm just curious about the lack of a "drop" key. I'm used to the 48SX and used that key often. Am I missing something? Thanks Mike M....

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  1. HP 35S drop key?

    I just got my 35S and so far like it very much. I'm just curious about
    the lack of a "drop" key. I'm used to the 48SX and used that key
    often. Am I missing something?
    Thanks
    Mike M.

  2. Re: HP 35S drop key?

    On Nov 27, 7:16 am, mikemo wrote:
    > I just got my 35S and so far like it very much. I'm just curious about
    > the lack of a "drop" key. I'm used to the 48SX and used that key
    > often. Am I missing something?
    > Thanks
    > Mike M.


    Unlike the 48 series, the stack on the 35S is fixed. Just go on with
    whatever task is next. Old values move from the X-register to the Y-
    register, Z-register, T-register, and finally drop into the bit
    bucket.

    If you have something else on the stack and need to get the current,
    no longer needed X value out of the way, just roll down the stack.

  3. Re: HP 35S drop key?

    In article ,
    cjmcc wrote:

    > On Nov 27, 7:16 am, mikemo wrote:
    >> I just got my 35S and so far like it very much. I'm just curious about
    >> the lack of a "drop" key. I'm used to the 48SX and used that key
    >> often. Am I missing something?
    >> Thanks
    >> Mike M.

    >
    > Unlike the 48 series, the stack on the 35S is fixed. Just go on with
    > whatever task is next. Old values move from the X-register to the Y-
    > register, Z-register, T-register, and finally drop into the bit
    > bucket.
    >
    > If you have something else on the stack and need to get the current,
    > no longer needed X value out of the way, just roll down the stack.


    On the earlier (pre-HP48) HP calculators, the "drop" operation also
    copied the T register into the Z register, while rolling down the
    stack will put the unneeded X value into the T register.

    If you want to minic the "old drop" operation on a 4-register stack, a
    sequence of HP-35s operations need to be performed:

    Start X Y Z T
    ------------------------
    R^ T X Y Z
    x<>y X T Y Z
    Rv T Y Z X
    ENTER T T Y Z (X vanishes)
    Rv T Y Z T
    Rv Y Z T T

    A much faster way to accomplish this would be to utilize the fact that
    a binary operation, e.g. "+", will drop the stack and duplicate the T
    register. So all you have to do is to add something which makes the
    value unchanged, i.e. add zero. Now the "<==" (Clear X reg) puts 0 in
    X, and then you can add this zero to Y:

    Start X Y Z T
    ------------------------
    <== 0 Y Z T
    + Y Z T T

    Just two keystrokes! Thys key sequence is so short that there's no
    point in programming it, since it'll take at least two keystrokes
    to execyte a HP-35s program....

    --
    ----------------------------------------------------------------
    Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
    e-mail: pausch at stockholm dot bostream dot se
    WWW: http://stjarnhimlen.se/

  4. Re: HP 35S drop key?

    On 28 Nov, 09:42, pau...@saaf.se (Paul Schlyter) wrote:

    >
    > If you want to minic the "old drop" operation on a 4-register stack


    That would be the "new drop", now, wouldn't it? Jeez!

    >
    > Start X Y Z T
    > ------------------------
    > <== 0 Y Z T
    > + Y Z T T
    >
    > Just two keystrokes!


    Clever!

    To be honest, I have to admit that I also have been accustomed to the
    flexible stack with the DROP function, although being an old user of
    the four level stack HP calculators of yesteryear (HP-21 was my
    first). So much that when the HP35s came into my hands I was at first
    irritated by the zeros just sitting there staring at me...

    Per.



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