[A83] Re: Ti83+ SE to 15MHz?

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[A83] Re: Ti83+ SE to 15MHz?


Yes, you're right, the information is in TI's latest manuals (Silver Edition
addendum), but here it is anyhow.
The new documented ROM calls are:
SetExSpeed EQU 50BFh
GetSysInfo EQU 50DDh
NzIf83Plus EQU 50E0h

The particular routine you need to worry about is SetExSpeed.  Run that
routine with A=0 for 6 MHZ, and A=1 for 15 MHZ.  You needn't worry about the
hardware version you're running it on (the call wont do anything on a
regular TI-83 Plus), but you do have to make sure the calculator is running
ROM 1.13 or greater.

Of course if you don't want to check the ROM version, you could cheat and
just output a value of 1 to port 20h if you want 15 MHZ, and a value of 0 to
port 20h if you want 6 MHZ.  However, in that case you'd have to check which
hardware you're running (20h is a shadow of the link port on a regular TI-83
Plus).  To do this you can use NzIf83Plus, but that would defeat the purpose
of not caring if you're on ROM 1.13.  To check the hardware version
directly, read the value from port 2.  If bit seven is set, you're running
on an SE, otherwise you're running on a regular TI-83 Plus.

About the LCD driver, you will most likely have to slow down whatever buffer
copy routine you're using (unless you're using GrBufCpy) if you're running
at 15 MHZ.

-Dan Englender

P.S. - Martin Virt is working on a faster mandelbrot generator, thought I've
never seen the one you're referring to.  (Hopefully he doesn't mind that I
mentioned it.)  I'd expect it to take well under a half minute on an SE.

----- Original Message -----
From: "Henk Poley" <HPoley@DDS.nl>
To: <assembly-83@lists.ticalc.org>
Sent: Monday, May 21, 2001 12:05 PM
Subject: [A83] Ti83+ SE to 15MHz?


>
> I've read that there was a certain romcall to set the Ti-83+ SE to 15MHz.
> What is that call? That would be really nice for the mandelbrot demo from
> the z88dk.
>
> 6MHz => aprox 10 minutes on a Ti83
> 15MHz => aprox 3 min on a Ti83+ SE ???
>
> Oh, uhmm, it's greyscale (IM2), are there anything that should be changed
> for "high speed"? Or is the LCD-driver-chip also 'overclocked'?
>
> And to not forget: How do you switch it back to 6MHz? Is there some flag
> that states the speed?
>
> Henk Poley
>
>
> PS: Okay, okay, it will probably be @#$RTFM@#$!!!
> But I (still) haven't downloaded them...
>
>
References: