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

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


> Van: Dan Englender <dan@calc.org>
> 
> 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.

I should bcall() them isn't it? For example:
	RST	$28
	defw	$50BF

The Z80ASM assembler hasn't got macros... And, yes, I could use the
INVOKE() command added lately

> 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.

It's for the startup code of the z88dk Small-C+ compiler, altough during
startup we don't use the linkport (de facto we don't use the linkport at
all, till someone write a routine for it...) I think I'll use the "safe"
one aka SetExSpeed. 2 bytes could be gained (switch on/off), but hmm, let's
stay compatible...

BTW: The romcall only works since ROM 1.13 ???
Is it normal to have ROM 1.13, or are there people who don't use it because
of bugs etc.??? Then I think I should to it "manualy"...

> 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.

Is there anybody already working on a Ti83+ SE IM2 greyscale interrupt???
And how slow is slow? Using IonFastCopy (or what it's called under
MirageOS) would get the "under water screen" effect when running on 15MHz?
Like on the *new* ROM 1.10 version of the Ti83, when you use an older
version of FastCopy?

> 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.

It's the one made by a member of the z88dk developers team...
Since the z88dk has quite recently support for the Ti's and, some more
recent, greyscale, the demo is quite new. We haven't posted it either at
Ticalc.org...
The program is about 3kb (Ti83), the size includes a second copy of the
screenbuffer (Horrible!!) and the z88dk's own floating-point routines...

If you want to try the compiler. Get it at:
http://z88dk.sourceforge.net/

> ----- Original Message -----
> From: "Henk Poley" <HPoley@DDS.nl>
> 
> > 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...
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