Slashdot Mirror
A C Compiler For The HP49g+
Cheese Source writes "As previously mentioned on Slashdot, HP's latest and greatest calculator is the HP49g+. While it sports a very powerful (for a calculator) ARM9 cpu, it is only 3 times the speed of the 49g, running at 4MHz. This is because it has to emulate an older processor. Of course, some calculator geeks are now writing adapting a free, open-source C compiler for it. Based on GCC, you can now make programs that run natively on the CPU between 12 and 203MHz. 1000 factorial is calculated and displayed in the blink of an eye (the built in command takes 30 seconds). It will also allow for some great games."
running at 4MHz. This is because it has to emulate an older processor
So what they're saying is, rather than porting their calculator software to a new platform, they found it easier to write an emulator that pretends to be the old processor? Sounds like a pretty crappy design decision to me.
Also, if customers are writing their own programs with a C compiler to get speed, why not just use something like the Zaurus running Linux, and one of the many, full featured, science/math software suites for Linux?
GCC has been available for a long time for the 68000 based TI calculators with TIGCC. Is this about a port of GCC that runs on the calculator?
Should only be about 3 years before Gentoo finishes compiling. Woohoo!
Perhaps the same that make TI calculators need 5 seconds to calculate 50!....
No, really. the 4Mhz cpu it emulates does imho only do 4bit arithmetic, so you need an awfull lot of cycles to handle longer arbitrary precission numbers...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
for those interested in the the 49g+ in all it's gory technical details.
peterrenshaw ~ Another Scrappy Startup
I suspect it was one of the two:
- Simple economics, if it's cheaper to use the faster processor and emulate the other one, it doesn't matter. Recoding for native operation may not have been possible. This is related to my second point:
- All glitches and problems with the existing design are well documented and hammered out. It may not have been feasible as I suspect there is a lot of verification that happens on these guys before they ship. If the calculator has been painstakenly debugged on one processor, it may very well be easier to insure 100% emulation than re-test all the functions.
..don't panic
See, now, your cart and your horse are transposed.
Specifically, the horse in this example is the chip, and the cart is, of course, emacs.
The C compiler is foundational. Now, we need to figure out an interface using the cable kit for a keyboard, and the relentless march of the One True Editor shall take yet another step.
Mwahahahahah...
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
Good to see that some programmers are interested in hacking a powerful calculator. They should be able to port great games, despite the rather low screen resolution.
I was already aware of that project, as an user of the TIGCC board (an environment development including heavily patched GCC for TI-68k calculators), which someone else already told about in those comments.
So how long until a NetHack port is complete? Come on, we all know what's important.
I don't want knowledge. I want certainty. - Law, David Bowie
Now with a C compiler available, how about building an Ethernet interface and porting the Contiki OS to iy? A Contiki port would bring TCP/IP networking, multitasking and a bunch of other cool stuff to the HP. Contiki has already been ported to a lot of weird stuff, like the GBA and the C64, so it would probably work well on the HP.
A long time ago i bought an HP41C (not "V"!) and it was (still is...) a very good, small & rugged machine. No nonsense. Back then HP were making the very best calculators in the world.
Nowadays, a certain Miss has decided to decimate the "Calculators" division of HP and it shows. THe present calculators at HP have the same look and (cheesy) feel as the TI calculators. They are bulky and large, they sport cheesy buttons and it is actually hard to find a model that supports the sooo efficient & fast RPN notation. In short: they suck. I feel like we will never ever again see really well built & designed calculators now. Too bad.
Interestingly enough, the only calculator left in their product line that still has the feeling & quality of true HP calculators is the "Financial" HP12C... It seems Economists have it all... !
Maybe we should petition for Agilent to start designing calculators? One can always dream...
No. Actually there have been tons of user complaints about how crappy the keys are on the 49g+. Check out comp.sys.hp48 on Usenet or Google groups. Supposedly they have been improved on recent calculators, but there are still complaints.
No, the Saturn has an external word size of 4 bits, but 64 bit registers and instructions.
At three to seven (the actual comparison) times the 4MHz 48g speed, there is far less than a gap of >>30 between the speed of the emulated processor and the physical one so I stand by (for now) my speculation that there is surely an algorithmic difference between the built-in (example?) one and the new 'native' one...
(But what do I know, I'm just flamebait... apparently...)
Note that Nickle will quite happily compute 10,000! (exactly) in a fraction of a second on a similar machine, through the miracle of Karatsuba multiplies. It also supports arbitrary-precision rationals and definable-precision floats (default 256b mantissa) with arbitrary exponent, and features a calculator-like interactive mode. I don't use much of anything else for numeric calculations anymore. (Of course, I co-wrote it.)
... think this calculator would, if nothing else be an amazing way to earn geek street cred? I mean, if programming (1 geek point) computer games (2 points) on an overclocked (3 points) calculator (4 points) using an open source (5 points) compiler isn't the pinnacle of all that is geek I don't know what is.
Hi,
I'm one of the people working on this. Maybe I can answer a few questions:
Whats the point? Why Bother?
Well, this is just an obscure hobby; no-one is spending 6 hours a day coding for this project. For me its just a way to learn a little about compilers. The main aim is to make it possible to create decent programs (mainly games) for this system. Coding for devices such as calculators has some interesting challenges to it, esp when you have to reverse engineer the hardware like we did.
Is this a real port of GCC? I thought ARM already has a port.
Yes it does, and its very good. We have tried to avoid modifying GCC itself to avoid extra work in the future. What we have done is write HP specific libraries and linking programs to executable may run. It works, so why not?
1000! in half a second is slow, 10,000! takes about a second to calculate on [some platform]
Indeed. Calculating factorials quickly is easy. Displaying the result (a massive, massive integer) is not. The factorial program trades off some calculation speed to markedly improve display speed. The "half a second" measurement comes from when the CPU is executing at 75MHz. I'm guessing running at 203MHz would speed that up a little.
Is the calculator really running a saturn emulator?
Yes, it is. SysRPL is an obscure language used only in these calculators. The complete Saturn CPU is being emulated, not just the SysRPL envrioment.
Yes, it makes things very slow - but there is a decade of debugged code written in sysRPL and Saturn asm. Throwing all that away would be very expensive for HP. With calculators, having the correct answer is critical. Emulating old code means the ROM should be fairly bug-free.
Of course an OS completely rewritten for the ARM would have been great - but its not economically feasible.
oops, some more I forgot
Is the 49g+ RPN?
Not by default - but you can set it to be with about 3 button pressed. Then its a proper RPN* calculator unless you set it back.
*The RPN it uses is different from HP's early implementation. The earlier versions have a 4 level stack only. The HP48/9 series effectlvly have an unlimited stack, and you can put all kinds of objects (matrices, programs, symbolics etc) on it. Its alot more powerful then the RPN of say a HP15c, but naturally more complicated to use
Will there be a linux/BSD/[other OS] port?
Well, you have a 203MHz CPU, 512kb RAM, and 2MB ROM. If you can fit linux on that then go for it!
What happens to the battery life when you run the ARM at higher clock?
I hold it, that a little rebellion, now and then, is a good thing. -- Thomas Jefferson
"1000 factorial is calculated and displayed in the blink of an eye (the built in command takes 30 seconds)."
So how big a display has this thing got if it can display 1000! Not sure how big it would be, my guess is somewhere between a googol and a googolplex.
Extra points for getting it posted on Slashdot and surviving it..
- Raynet --> .
... is nigh.
See, the only thing that's been preventing the gameboy from being a kickass calculator is the relatively awful control system. However, the upcoming DS has two screens, one of them a touchscreen; you can't get a better small-platform simulation setup than that, IMO, since you can change the key layout per task, and if nessecary trade the keys temporarily for a whole second screen.
It's like a palm pilot calculator, except that it still has a screen while the keys are up, eliminating the most sucking thing about palm pilot calculators.
Seperately, you never need to bother with a connection cable, because it does 802.11, and the screen is quite nice - backlit 256x192 fullcolor with hardware-assisted 3D with antialiasing. The graphing potential of such hardware is massive. You can use sprites for things like cursors and flow analysis.
Oh, right: and the underlying CPU blows the doors off of a 4mHz ARM9. It's got a 66mHz ARM9 *and* a 33mHz arm7. 8 meg of ram for large matrix calculations. The ability to network.
Oh, and games on a gameboy are better than games on any TI.
The end is nigh. HEED MY WARNING. Calculator advocates, repent - unification is at hand, commodity hardware defeats characteristic purpose hardware, generalization is cheaper than specific hardware, the ASIC falls at the sword of the CPU.
Linux boxes for VCRs, Linux boxes for game systems, Linux boxes for kitchen appliances, but when it matters, turn to Nintendo for your calculator.
And in case you were wondering, yes, I'm the gameboy stonecypher, and yes, my calculator, based largely on gnuplot and yacas, is about three quarters done. I may not know shit about math, but my Nintendo sure does.
+1, Insightful to anyone who compares YACAS and whatever other computer algebra systems there are to HP's bujillion calculators I can't be bothered to research.
StoneCypher is Full of BS