Maybe it'll include more memory, too.

Looking at the French board (Babelfish translated), and seeing the ROM size there, I believe that it is the same, or at least the same useable area.

That looks cool, it would be nice if it had a newer OS on it too. And why 16 MHz, wouldn't it make more sense to have it running a lot faster, like 35 MHz. I wish I could get one, but I already have a ti-89 ti and my parents would not buy me another calculator, and I have no money.

Because it can only go so fast. The 68k is a cpu without a cache, so frequencies are limited by the ram/flash.

In theory this is 33% sppeed improvement over HW2/HW3. There is one other variable that affects performance. So heres a question for Oliver: Do you know the value the OS writes to the ram/flash wait state register $600003 ?

I think that the fastest a 68k chip will run is 33 MHz, so why don't they make it that fast. I might be wrong, but I have an old mac running a 68k CPU at 33 MHz so I would assume that a calculator on a 68k chip could run that fast.

Take the chip out of the Mac and put it in your TI - provided they're sockets.

The 89 is not socketed. That would increase the cost a bit, eroding TI's profit margins. There's no really good reason to socket the processor, anyway.

Does your Mac have a 68000 or a 68020 CPU?

All the Macs and processor upgrade cards at lowendmac.com that are 33MHz are 68030s.

I had an Amiga 600 with a 40MHz 68030 upgrade card.

The 68040 and 68060 had even faster speeds.

HP's calcs have 75MHz CPUs in them (and an infrared link port and a SD slot) ~ I'm still waiting for TI to catch up...

TI's calcs are far more user friendly though- with HP's I've heard there's like a lot of commands you have to memorize, whereas on TIs they are in menus.

Why can't TI just put a MC68040 CPU in it?

Because they aren't fully compatible, the 68040 chips use the 1010 and 1111 instruction lines for new instructions, whereas TI uses the 1010 and 1111 line emulators in the 68000 for other purposes. So AMS is not compatible with a 68040.

<<Do you know the value the OS writes to the ram/flash wait state register $600003 ?>>

It's the same value as the one for HW3 since AMS hasn't changed (and the boot code doesn't seem to initialize it anyway).

<<In theory this is 33% sppeed improvement over HW2/HW3. >>
I wouldn't say "HW2/HW3: 12Mhz. HW3: 16Mhz". It seems to be a bit more complicated than this.
I have written a small tool (link above) specially for the HW4's CPU speed measurement (I preferred to trust my own code for this; any suggestion to improve it are welcomed). I get :
- TI-92 Plus HW2: 14.05 Mhz
- TI-89 Titanium HW3: 12.79 Mhz
- TI-89 Titanium HW4 : 16.07 Mhz
And as Pollux emphasized in yAronet's discussion, the execution time of the instructions may depend on the instructions executed, it's more complicated than just couting the number of cycles (and using interrupts for the measurement may not help), so the absolute values shouldn't be taken as is.

TI-Vibe is also an excellent tool to measure the relative speed: just compare the sound you get at a given sample rate on different calculator models. Yes, I have to set a higher sample rate for my 92+ HW2 to get the correct sound, it *is* faster than my Titanium HW3 :)

Are there any other benchmarks? Like frame rates for the FAT engine or any of the several mode 7 engines ?

I looked at the code. I'm not sure why you're adding the highest bit of the remainder to the quotient? Remainders aren't fixed point math. Shouldn't the logic be:

denominator = 10000;
quotient = x/denominator;
remainder = x % denominator;
if (remainder >= (denominator/2))
{
quotient += 1;
}

Thanks, you're right, I've fixed it (fortunately the result doesn't change much).

Is it possible to overclock the cpu of earlier HW revisions to get them up to par with HW4?

I don't know about the ti-89 titanium, but the ti-89 can be over-clocked by looking at the link

This page has a guide to overclock a TI-89. I wonder if a 33pF condensator would overclock it to HW4 level, if a 22pF overclocks it to approximately double clock speed?

I'm assuming this is released in the United States...

Hopefully I can save enough to get this. New hardware is nice, but too bad they can't put in a regular headphone jack...

I suspect the minijack was a tradeoff between cheap and teachers. It's really easy and incredibly cheap to use a predefined, standard hookup, when compared to making an in-house solution. They needed one out, one in, and one neutral. Stereo headphone jacks fit the bill perfectly: three channels, and a hookup that the target audience is already familiar with and, for all intents and purposes, can't screw up. It's really hard to insert a link cable backwards. The other consideration is teachers. When presented with a choice, they'll probably go with the calculator that doesn't let students use it as an mp3 player. (In my high school, if you had a device that played music [iPod, CD player, whatever] you got three days suspension and the device confiscated until your parents came and picked it up. CDs without a player just got confiscated unless you had a teacher's note.)

The new USB ports are a pre-made spec., ready for transmitting bigger files faster. Yes, you can screw up and plug it in backwards, but you have to push really, really hard (no personal experience).

suspension for a cd player? that sucks. what's the logic behind that? If I couldn't bring my mp3 player to school to listen to on the bus, I would go crazy.

Yup. And a week or possession of cell phone.

And that's why people always wondered about those odd adapters I always carried…

that is a bit strict. getting in trouble for possessing a CD player when I was in High School it seemed like all that happened if you were listing to music when you shouldn't be was they told you to stop or in the worst case you're player got taken away. what sort of evile people run your school?

The old principal was a Luddite.

That would really suck, I always listen to music on my laptop during study hall. We are not really allowed to, but I do it anyway. The worst they will do is tell you to put it away, and then the next day they forget all about it.