
KnightOS – an open-source operating system for TI calculators - MaxLeiter
https://github.com/KnightOS/knightos
======
jevinskie
I've watched this project on Github and have been impressed by its rapid
evolution. At least on certain models, KnightOS is only possible thanks to a
private effort to factorize the firmware's 512-bit RSA keys. [0]

[0]:
[https://en.wikipedia.org/wiki/Texas_Instruments_signing_key_...](https://en.wikipedia.org/wiki/Texas_Instruments_signing_key_controversy)

~~~
ryan-c
I liked the way the factorization was announced[0].

    
    
        Fun Number Theory Facts  
          
        Gentlemen,
        
        A mathematical morsel for your entertainment and edification.
        
        The number
        6,857,599,914,349,403,977,654,744,967,
        172,758,179,904,114,264,612,947,326,
        127,169,976,133,296,980,951,450,542,
        789,808,884,504,301,075,550,786,464,
        802,304,019,795,402,754,670,660,318,
        614,966,266,413,770,127
        
        is the product of
        5,174,413,344,875,007,990,519,123,187,
        618,500,139,954,995,264,909,695,897,
        020,209,972,309,881,454,541
        
        and
        1,325,290,319,363,741,258,636,842,042,
        448,323,483,211,759,628,292,406,959,
        481,461,131,759,210,884,908,747.
    

0\.
[https://web.archive.org/web/20090805011013/http://www.united...](https://web.archive.org/web/20090805011013/http://www.unitedti.org/index.php?showtopic=8888)

~~~
sneak
I mean, really - they used a non-trivial but practically workable _math
problem_ to block features from _calculator enthusiasts_. What did they expect
to happen?!

~~~
TeMPOraL
Maybe at the time the problem was intractable?

~~~
stephengillie
It's always seemed somewhat tenuous to tie our operational security to our
rate of technological advancement. Though maybe it's more of a statement about
our ability to generally understand our rapid advancements.

~~~
vidarh
It is the recognition that almost all secrets are only valuable for an amount
of time, and that you generate keys on the basis that within that time, it
will be much more expensive to attack the keys than to attack something else.

------
striking
Past comment thread:
[https://news.ycombinator.com/item?id=7896990](https://news.ycombinator.com/item?id=7896990)

More info/online demo: [http://www.knightos.org/](http://www.knightos.org/)

It's really neat how you can target this to write C applications for TI-84s.
Take for example,
[https://github.com/MaxLeiter/CoreLibCDemo/blob/master/main.c](https://github.com/MaxLeiter/CoreLibCDemo/blob/master/main.c)
. If you don't want to use assembly, you don't need to. It's pretty neat.

~~~
MaxLeiter
the issue with using C is that filesizes are huge compared to an equivalent
program in asm

~~~
striking
Of course. But it's neat, no? It could make prototyping for the platform a lot
easier, before one commits to writing out the ASM for their app/game.

~~~
MaxLeiter
Oh, it's super cool (I made the demo you linked d:), just pointing that out
for people potentially interested in writing C programs for KOS (as it is a
limitation)

------
ddevault
Lead dev and project founder of KnightOS here. Nice to see it on HN again :)

Happy to answer questions.

~~~
zokier
Do you see some practical benefits of KnightOS or is it more just because we
can and its fun? I mean is KnightOS equipped calculator really
useful/convenient for something that vanilla TI is not?

In contrast the other open calculator project I know, WP34s, aims to create
the best HP style calculator they can based on HP HW. Is your aspiration
similarly to make a really good TI style calculator?

~~~
ddevault
Well, from a design and usability perspective, KnightOS is much more
sophisticated. It supports multitasking and has a package manager and so on.
That being said, there is poor support for math (yeah, really). I want to
polish that up until it's suitable for classroom use, and then use it as a
platform for promoting open source in schools and getting kids interested in
programming/hacking in school. KnightOS is basically a Unix system, so it'd be
nice to help bring those concepts into the hands of student tinkerers.

------
medina
Which make me to check and... a TI-89 is still over $100.

~~~
Igglyboo
The product doesn't need updating and they have no competition so why lower
the prices?

If you want something newer with more power and more features they also have
the Nspire line of calculators but the TI-89/TI-83 basically the staple
calculator for highschool math.

~~~
rz2k
> they have no competitors

That is exactly why it would rub people the wrong way on a site where people
are interested in entrepreneurship and also in disruption. Being approved by
standardized testing institutions becomes a barrier to entry and a means for
rent seeking. Of course there could be far better calculators for lesser cost
that aid learning better, and more clearly reflected the types of tools that
should be the default quality for practitioners in the real world.

Compare the HP-12c in finance. It's extremely well-designed and optimized for
a lot of patterns, and it even has a moderately steep learning curve that
seems to enamor it to its users, yet it is absurd to argue that absent
certification as an approved calculator for the CFA that there would not be be
even better handheld calculators used more often that people spent time to
learn.

The TIbcalculator doesn't address either demand that goals of high school
mathematics should address. It doesn't expose students to the state of the
art, _and_ despite its constrained capability it is costly enough to shrink
the talent pool of high school students who get to take the tests that show
off their aptitude and achievement.

~~~
thaumasiotes
A calculator is necessary for the AP calculus test; calculators are allowed,
but not necessary, for the SAT.

~~~
zhte415
Genuine question: It is nearly 20 years since I was in post-secondary
education:

Why would calculators be needed for a calculus test?

~~~
thaumasiotes
To calculate certain definite integrals that you wouldn't expect a person to
do by hand.

------
0942v8653
I got a TI-84 Plus CE, which is the most recent version of the calculator
(same screen as the Color Silver Edition, but with a faster CPU and a
different case). A bit dissapointing to see that nothing has come out for it
yet, but Doors CS is working on it -
[https://www.cemetech.net/forum/viewtopic.php?t=11997](https://www.cemetech.net/forum/viewtopic.php?t=11997)

------
nzoschke
I learned to program on my TI-85.

First I read the manual and made simple Basic programs by hand.

Then I found online resources to copy and modify.

#ticalc on Efnet was a great community. They turned me onto making a homemade
PC link cable, loading custom firmware, and downloading and writing programs
in Assembly.

The screenshots in the KnightOS header are extremely nostalgic.

I'm glad to see the TI hacking tradition continue.

~~~
dogma1138
TI's were the closest thing that some one who was born in the mid to late 80's
to early 90's had to an "old school" PC's. If you were born after 84's most
likely the 1st computer you had to deal with would've been already running
Windows, (MS-DOS)Norton Commander/Customized Shell or something similar and
came with a manual which thought you how to call a 1-800 number to load a disk
rather than BASIC.

