HPGCC applications and battery life? - Hewlett Packard

This is a discussion on HPGCC applications and battery life? - Hewlett Packard ; I recently realized that if I run C programs on the HP 50g it seems to drain battery life quicker than normal. When running a C program on the 50g, is the CPU running constantly at full tilt? In normal ...

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Thread: HPGCC applications and battery life?

  1. HPGCC applications and battery life?

    I recently realized that if I run C programs on the HP 50g it seems to
    drain battery life quicker than normal. When running a C program on
    the 50g, is the CPU running constantly at full tilt? In normal
    everyday number crunching, the CPU works for a short time, computes
    the answer, displays it, and then sits idle for most of the time. In a
    C program, does it never idle?

    I've never used HPGCC before, but I have loaded some programs written
    with it onto my 50g.

    Thanks,

    S.C.

  2. Re: HPGCC applications and battery life?

    > I recently realized that if I run C programs on the HP 50g it seems to
    > drain battery life quicker than normal. When running a C program on
    > the 50g, is the CPU running constantly at full tilt?


    No. In fact, the default behavior is to set the clock speed to 12Mhz,
    which is the same speed of the the idle calculator when it is waiting
    for you to press a key. You have to specifically tell it to switch to
    high speed in your program.

    TW

  3. Re: HPGCC applications and battery life?

    On Dec 21, 11:12*pm, TW wrote:
    > > I recently realized that if I run C programs on the HP 50g it seems to
    > > drain battery life quicker than normal. When running a C program on
    > > the 50g, is the CPU running constantly at full tilt?

    >
    > No. *In fact, the default behavior is to set the clock speed to 12Mhz,
    > which is the same speed of the the idle calculator when it is waiting
    > for you to press a key. *You have to specifically tell it to switch to
    > high speed in your program.
    >
    > TW


    Ah. Thanks for the clarification. I must have simply been using the
    calculator more.

    S.C.

  4. Re: HPGCC applications and battery life?

    On Dec 22, 1:42 pm, sc_use...@hotmail.com wrote:
    > On Dec 21, 11:12 pm, TW wrote:
    >
    > > > I recently realized that if I run C programs on the HP 50g it seems to
    > > > drain battery life quicker than normal. When running a C program on
    > > > the 50g, is the CPU running constantly at full tilt?

    >
    > > No. In fact, the default behavior is to set the clock speed to 12Mhz,
    > > which is the same speed of the the idle calculator when it is waiting
    > > for you to press a key. You have to specifically tell it to switch to
    > > high speed in your program.

    >
    > > TW

    >
    > Ah. Thanks for the clarification. I must have simply been using the
    > calculator more.
    >
    > S.C.


    Perhaps, perhaps not. Since you didn't compile them yourself, you do
    not know what the programmer did. It is true that the default
    behavior is to default to 12Mhz. But I suspect that many C
    programmers may clock up the processor to 75Mhz and remain there even
    when waiting for input burning batteries.

    Many of the HPGCC examples have sys_slowOff() calls, it would be easy
    to copy one for one's own program without thinking about clocking down
    for input. If you have the C source check it out. Add sys_slowOn()
    before input statements and sys_slowOff() after.

    If there is no input (i.e. takes from the stack, computes, returns to
    stack), then you have a choice run faster/shorter, or slower/longer.
    I doubt that the runtime proportional to the clock rate. Faster is
    most likely less efficient shorting battery life.

    What is the C program? It is publicly available?

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