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

To: <assembly-83@lists.ticalc.org>
Subject: [A83] Re: Ti83+ SE to 15MHz?
From: "Dan Englender" <dan@calc.org>
Date: Tue, 22 May 2001 15:40:44 -0400
References: <0c9de4338141651NET013S@hetnet.nl>
Reply-To: assembly-83@lists.ticalc.org

> 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

Yes, they need to be B_CALLed.

> 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...

What I meant si that if you access port 20h in a regular TI-83 Plus, it
would be the same as accessing port zero (the link port).

> 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"...

Yes, the ROM call only exists on ROM 1.13.  You'll probably get a crash
trying it on a different ROM version.  You can use the ROM call to check the
ROM version (which exists on all ROM versions) to make sure you're on 1.13.
SE's must use 1.13 or higher, but most regular TI-83 Plus users will still
have 1.12 loaded.

> 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?

I don't know if anyone's playing around with greyscale on a SE.  I haven't
tried.  If you use IonFastCopy while running at 15 MHZ, it wont copy the
screen correctly at all (that may be what you mean by the "under water
screen").  When I'm running something at 15 MHZ, I either change back to 6
MHZ when talking to the LCD, or just use GrBufCpy. However, it should be
fairly easy to modify the fastcopy routine to work at high speed.

>
> 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...

Martin's uses fixed point maths.  Perhaps that's why it's faster.  (Why
would you need a second copy of the screen buffer on an 83 Plus?  There are
more than plenty amounts of free space to use.)

-Dan Englender


> 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...
>
>
References:
[A83] Re: Ti83+ SE to 15MHz?
From: "Henk Poley" <HPoley@DDS.nl>