Date:     Mon, 20 Mar 1995 17:05:53 -0800
From:     Larry L Bauer  [larryb@hevanet.com]
Subject:  LZ: TURBO mode...

This message comes from the List-ZShell mailing list:


>Everyone says that the TURBO upgrade worked great, but did
>anything go wrong for anyone?  If so, I'd like to know when
>I upgrade mine.

    I have found that the screen contrast is a little dimmer when you are
using turbo mode (I have a turbo switch).  I think this happens because the
LCD runs on a different clock than the calc.  So when the calc is running
zshell, the screen is a little lighter.  When the calc is in the home screen
doing nothing, the screen is normal.
    This has not ever been a problem for me.  All I do is turn up the
contrast a little and run zshell.  I have tried everything I can think of on
the calc and I have found no other problems.  I think everyone should have a
turbo switch!!

One note:  The calc has a seperate clock that initiates interrupts to the
system.  This is where the screen gets it's refresh clock (I think). By
locking on to this interrupt you can get a constant speed even when the calc
is in turbo mode!

Example:  here is a little program that puts out pulses to the link port
using the interrupts.  You must have a calc with a turbo switch to compare,
and some headphones to listen to the pulses.

Keys:
        press '+' to turn on the sound.
        press '-' to tun it off.
        press 'F1' to 'F5' for some cool effects!!!
     
