Omnimaga
Calculator Community => TI Calculators => ASM => Topic started by: Hot_Dog on April 20, 2011, 10:41:47 am
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As an ASM programmer, I like to discover what calculators can do, just like anyone else on this site. I like to find out for myself what works and what doesn't. If you tell me "it's not a good idea," that's fine, but that doesn't mean it doesn't work. I can be allowed to try, can't I? And in trying, I discover things that DO work.
I've asked at least two ASM questions on this site recently, with answers that I know people can provide. Whether or not the final goal I have is hard or even bad, the fact remains that the question I ask has an answer. For example:
If I ask how to restart crystal timers, it may not be a good idea to run interrupts every 16 cycles, but that doesn't mean I can't know how to restart crystal timers, right?
If I ask how to unlock flash, it shouldn't matter that it's recommended I stick to IM 1...you can still tell me how to unlock flash, no?
As this site is designed to help people learn, if I have a question that can be answered, please answer it. Despite my unrealistic goal, I can still learn something for future use rather than fishing for answers. Posts that simply state "I don't recommend this" or "why do you want to do this" without answering the question, unfortunately, let me down and discourage me because I feel that people think I don't know what I'm doing.
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I couldn't agree more. If we don't know the answer, we either don't post or post something useful. Not saying 'Why do you want to do this?'. If we say 'I don't recommend it', please say why.
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If we say 'I don't recommend it', please say why.
And even then, we can still be told how to do it :D
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If we say 'I don't recommend it', please say why.
And even then, we can still be told how to do it :D
The more information the better, you'll be thanked, perhaps rated up and we'll answer your questions too. (I'm not talking to Hot_Dog, to everyone who reads it).
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I don't know of many people with those questions. I personally try to answer questions that I know even if for the simple reason is to show off what I know. However, it should also be noted that some of the ideas are simply complex and difficult to explain :/
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Hmm I hate when people do that. You should warn them via PM (or temp-ban them) because this is against Omnimaga rules. When someone asks a question, it's because he wants to know how to do this. People should at least answer him. If he asks why you want to do this, fine, but at least he should answer.
One issue is that you may have a potential new discovery/innovation, and it requires the usage of an unconventional method. This attitude from these people goes against the TI community and I would like if it did not start happening again like in 2007.
By experimenting, it's how we discover how to do things like TI-Boy SE. However, to experiment, people may need help, and telling them to not bother will not allow them to achieve things like TI-Boy SE.
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With calc84's response. I think that was mostly because you said you were setting your interrupts for once ever 16 cycles. Which he was right, you can't do anything with that. But what you actually meant was more like 150 cycles. So I think that was just a simple misunderstanding.
But with the flash stuff, that's always been an area of hesitation. Changing the OS takes care and the original flash unlocks took several months of research before they were found. So the actual information was originally hard to get. And then, people don't want just anyone to be able to do stuff to the OS because it can lead to problems like flash corruption and deleted certificates. I don't remember where I heard it, but I remember a quote, "If someone can't figure out how to modify the OS, maybe they shouldn't be doing it." I don't necessarily agree with it, but that has been a thought. So that's probably why no one would answer your question about unlocking flash. But you did get the routine eventually though right?
Sorry if that sounds mean, but unlocking flash used to be a touchy subject. FloppusMaximus actually got a DMCA about his original flash unlock.
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thepenguin77, I see what you're saying and it makes sense.
However, just for the future, it would be nice for an answer like "I don't think that's a good idea because 16 cycles is too short yadda yadda yadda...BUT, nevertheless, here's how to keep the timers going."
As for the flash, I see, but I was just mad that I didn't recieve ANY answer...even if I had been told "We can't tell you, and here's why...it's for safety of calculators, it's extremely hard, there's a chance of a DMCA, yadda yadda yadda," then I would have been given an answer. I thought flash unlocking would be easy, so when I didn't recieve an answer I thought it was because people felt I shouldn't be making a custom IM 1 routine, so you can see why I was thinking "So? That's not what my question was"
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Yeah, sorry I didn't give you a more specific response. Flash stuff is more IRC talk anyways.
But don't forget, once you get flash unlocked, that's only half the battle. You still have the whole task of actually getting the modifications in the right place. A task during which I have destroyed about 200 wabbitemu OS's and about 10 real calculator OS's. :D
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FloppusMaximus actually got a DMCA about his original flash unlock.
Are you serious? O.O Also when was that? *wonders what was violated by unlocking flash*
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Probably they didn't want people to edit the OS x.x
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I can't vouch for it's correctness or even if it's what I think it is(seeing as how I don't know z80 very well), but I believe the flash unlock is part of this routine:
Click here (http://brandonw.net/crap/answer.txt).
Obvious warning: Don't touch the certificate(unless you're sure you know what you're doing).
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FloppusMaximus actually got a DMCA about his original flash unlock.
Are you serious? O.O Also when was that? *wonders what was violated by unlocking flash*
Ok, so this (http://www.detachedsolutions.com/forum/index.php?t=msg&th=240) is what I remember reading. It was not a DMCA, but it was pretty close. Of course I don't know the whole story (I was 9 when that was posted), so you'll have to get someone older to explain what really happened.
And since I had to go hand copy the link from my old computer, here (http://www.detachedsolutions.com/forum/index.php/mv/msg/2418/0/15/) is the topic that I've had favorited for over a year from which I figured out how to unlock flash. It's by floppusMaximus and you can see on page 2 how cautious everyone is getting. It's pretty vague on the details so it took me quite a while to figure out how to do it...
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I believe that one of TI's lawyers contacted them about distributing TI code, and told them not to.
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O.O
Wow.
I am looking at that link, now! I don't want to use it, but I want to know how to :)
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Yeah, I'm sorry about my response. I didn't have time to go into the details of answering your question, but I did notice the 16-cycle thing. I apologize if that came across somewhat rude.
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thepenguin77, I'm assuming then that Netham45's linked code only writes flash, not unlocks it?
Yeah, I'm sorry about my response. I didn't have time to go into the details of answering your question, but I did notice the 16-cycle thing. I apologize if that came across somewhat rude
Oh, not at all! Actually I didn't think you were rude.
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Ok, so this (http://www.detachedsolutions.com/forum/index.php?t=msg&th=240) is what I remember reading. It was not a DMCA, but it was pretty close. Of course I don't know the whole story (I was 9 when that was posted), so you'll have to get someone older to explain what really happened.
And since I had to go hand copy the link from my old computer, here (http://www.detachedsolutions.com/forum/index.php/mv/msg/2418/0/15/) is the topic that I've had favorited for over a year from which I figured out how to unlock flash. It's by floppusMaximus and you can see on page 2 how cautious everyone is getting. It's pretty vague on the details so it took me quite a while to figure out how to do it...
Haha, I remember those discussions (good old thread #240...)
I did eventually find a simpler and more robust version of the technique I was talking about in that second thread, but I don't know if I ever released that; it's SE-only, of course. What I would currently recommend using is the technique used by DuckSign, which is based on Brandon's well-known exploit, but much more robust.
But...
It is dangerous to write to Flash. It's not a matter to be approached lightly. The Flash protection is sometimes annoying, but it's actually a very nice feature, because it means that you can run all kinds of assembly programs, with nearly unrestricted access to the hardware, without worrying that your data could be corrupted (or worse, your calculator made unbootable.) Every time somebody writes a program to work around that protection - no matter how skillful or how careful the programmer - that creates new risks, makes users less safe. If you can do what you want to do without writing to Flash, or only using the supported API - and, most of the time, you can! - we are all better off. I'm not going to tell people what they can and can't do, but these are things you really need to consider before releasing such a program.
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Hot_Dog, actually, that routine Netham gave will both unlock and write to flash. And I assume it will return with it unlocked. BrandonW find's some pretty weird glitches. :)
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This is why I am glad I have an emulator :) That way if I ever dabble in writing to flash I can very thoroughly test it and recommend it not be used on an actual calc XD
Ooh, that actually makes me wonder if emulators should have a way for some programs to detect if it is an emulator... That way if it isn't, you could make your programs not execute certain code :D
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Hot_Dog, actually, that routine Netham gave will both unlock and write to flash. And I assume it will return with it unlocked. BrandonW find's some pretty weird glitches. :)
Now this is a curosity question, since writing to flash is dangerous...does the routine work on all operating systems?
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Ooh, that actually makes me wonder if emulators should have a way for some programs to detect if it is an emulator... That way if it isn't, you could make your programs not execute certain code :D
Seems like that would be a bug in the emulator, don't you think? :P
(There are various seldom-used aspects of the hardware that most emulators don't properly handle; you could probably find one of those to exploit. But don't be surprised if later emulators fix those holes. One of my personal goals for TilEm 2 is to eliminate as many of them as possible.)
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Yeah, but I mean maybe you could make an unused port return a certain value or something? That could be useful in some situations. Heck, maybe you could make those ports do things like have the LCD mapped to a spot in memory and then people could make emulator only games XD
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AH I remember that thread now. I joined Detacheds around late 2003 (I was Kévin9999 back then because there was another Kevin user and that was the nickname I normally used on forums). I didn't read the entire thread but I remember the discussions about third-party OSes and TI sending C&D letters.
I wonder if that was because back then they were selling APPs and they were scared that people would make it easy to pirate their stuff or steal their code?
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Yeah, but I mean maybe you could make an unused port return a certain value or something? That could be useful in some situations. Heck, maybe you could make those ports do things like have the LCD mapped to a spot in memory and then people could make emulator only games XD
I suppose we could do something like that. With the ability for the user to disable it if programmers abuse the feature.
The idea of emulator-only games seems a little silly, but maybe if folks in the community wanted to get together and produce a new, fictitious hardware design (Omni-84 Plus Iridium Edition), we could support that as an alternative to the "real" calculator models.
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Yeah, that was more along the lines I was thinking ! Of course all that would need to change is the addition of new ports and we could be set ^-^ It could have the flash and whatnot unlocked and users could have fun with that :D
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I agree. That said I'm unsure if it would get an audience as big as real calculator games, though. I think many people who use calc emus use them to debug and test stuff they work on.
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Well, yeah, that has to be our primary focus; in order to be useful for debugging, it needs to be as faithful as possible to the real hardware. But, if people wanted to have a virtual calculator with 2 MB of RAM and a 100 MHz CPU, that would be easy enough to do, and maybe useful for some purposes.
Now this is a curosity question, since writing to flash is dangerous...does the routine work on all operating systems?
If you're talking about Brandon's write-to-user-Flash routine - yes, I think it works on all current operating systems. Whether it'll work on future OSes, of course, is anybody's guess, but one of the things that bothers me about Brandon's routines is that they don't do any sanity checks to see whether the OS will work or not; they have no failure mode except to crash.