68K, because:

1. It's faster than the z80
2. C programming is already available for it
3. It's assembly dialect is easier than that of the z80
4. 16 32-bit registers, each of which can be compared to the next (no need for an accumulator)
5. It's inexpensive
6. All of the best calculator games are written for the 68K chip

My second choice would be an ARM-compliant CPU, because not only is it 32-bit in nature, but also it's a hell of a lot faster than both current CPUs. The only grudges I have against it is that it's assembly dialect is difficult and it's more expensive than the 68K.

And while we're at it, it would be good to have a faster LCD screen, too. Perhaps a 16-bit TFT color screen?

1. not necessarily: 84+ has 15MHz Z80, v200 has 12MHz68k
2. and z80: z88dk
3. I have no idea; point conceded
4. see #3
5. see #3
6. only because the OS, screen resolution, and display drivers are better

1. Comparing clock speed between two different CPUs is completely meaningless. E.g. 1 MHz 6502 = 3 MHz Z80, 1 MHz 6809 = 20-100 MHz (in the right situations) Z80. And that's still comparing two 8-bit processors.

2. Which produces bloated code that runs at the speed of TI-Basic.

Yes, comparing clock speeds is completely pointless (it drives me crazy when computer manufacturers do it). What makes the 68K processors faster is the more flexible instruction set, expanded registers, and I'm guessing that it takes less clock cycles to execute each instruction. What also makes the comparison pointless is that you can run a processor at just about any speed up to its max limit, so if you wanted to "prove" that a Z80 was faster, you could run it at 10 Mhz and a 68K at 100 Hz (which would probably be too slow for the memory refresh, and the RAM would lose all the data, unless it's SRAM).

clock speed itself is meaningless

z88dk is not too bad. Based on my experience with Small-C (which is an older project based on the same code), it produces programs that are about three (or more) times as big and slower than assembly written by an experienced assembly programmer, but it's nowhere near the slowness of BASIC. It's faster than BASIC by about an order or two of magnitude.

Besides, you can write some speed-critical functions in assembly quite easily using z88dk, as opposed to calling an assembly program from BASIC using a weird calling convention to pass arguments to it.

C for the Z80 calcs has the advantage of being an easy language that's fast enough for most purposes. It's also not as limited in capabilities as TI-BASIC, either (local variables comes to mind). Of course, for simple and predominantly math-oriented programs, BASIC is still better.

If nothing else, it's a good language for prototyping a program.

1. But a Dragonball chip (based on the 68K chip, but with more capabilities) is 66 MHz. But as mentioned above, speed comparisons between processors is pointless...
2. TIGCC is superior to z88dk, and C code easily compiles into efficient 68K assembly.
3. move.w #6,%a0

4.
5.
6. Also in part that we have TIGCC as well as an easy assembly dialect, drawing more developers and thus fresher ideas to the platform. Additionally, the chip has the means to implement more advanced types of games and graphic algorithms because of it's 32-bit nature and the broader instruction set.

It would probably be based on either the Z80 or 68k regardless...if it wasn't, TI would have to do a major porting job to the new processor.

Even then, Z80 is the coolest. It's totally undeniable. :-)

They could probably make an emulator like for HP calculators.

R800!!! (link)

One option would be the Renesas SuperH SH7705 32-bit RISC microprocessor. It is a 32-bit, ultra-low-power microprocessor that runs about 100Mhz. Checkout the link for more info.

Anyone that suggsts Celerons because of built-in WiFi should be shot. We've already discussed the pros and cons of calc WiFi at length.

Anyone who suggests a full fledged desktop CPU is stupid.

...unless it was used in desktops over 20 years ago (more or less). :) Remember that the first Macs used 68K's, & the TRS-80 used a Z80, & they were considered desktop computers. Perhaps 10 years is enough...I hear they have some 80386's (or were they 80486's?) that do not require cooling. That would be really cool.
About the power...it could use something like a laptop or cellphone battery (since they hold more, AFAIK) which one would recharge every night.
My PDA runs 400MHz with no cooling, & I only recharge it once every few days (but it does not do calculus or algebra, unfortunately).

Now that I think of it...why not just make a free CAS for a fast PDA? I would if I knew how. If it became ubiquitous, they would eventually have to allow them or risk having their tests severely outdated.

You can use the emu48 (an HP emulator) on a Palm or a PocketPC.

You have to provide your own ROM file.

HP makes the ROMs of the HP48S and HP48G available for free download.

You can download the source code of the HP49G ROM(complete with CAS) for free undel LGPL. Compile it, and you can use it with emu48 too.

>>the first macs had 68k cps
and the first macs sucked :)

not as badly as modern Windows do

Harhar Mac-using is a mental disorder, harhar. Any computer that is produced by only one manufacturer SUCKS!

By your (il)logic,
- TI-83+'s suck.
- TI-89's suck.
- TI-92+'s suck. (etc.)
- Suns suck.
- xServers suck.

You were probably joking, so I'll give you the benefit of the doubt and let you off with just a warning this time. :-D

Actually, Macs are produced by as many companies as, say, Dells are.
My Mac has a Nvidia GeForce2 MX display, a Pioneer DVD-DW DVR-104 SuperDrive, a G4 processor manufactured by Motorola, an Apple Pro Mouse manufactured by Fujitsu, an Apple Pro Keyboard by Mitsumi Electric, and a host of chips made by probably as many other companies. And you call that one manufacturer.

hey, what? my apple pro mouse is made by logitech!

Celerons don't have built-in wifi... Do you mean the *Centrino* **CHIPSET**?

Yeah, and the Centrino chipset includes a Pentium M instead of a Celeron, IIRC.

Depends, sometimes it has a Celeron M processor, which is basically the same thing except with a smaller cache.

My bad.