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Show HN: KnightOS – An open-source OS for calculators
- qwertyuiop924 10y agoI hear Drew's done some great work with this. I'd look at it myself, but flashing my calculator firmware is a bit risky for such an overpriced device. Thank you, College Board.
- Sir_Cmpwn 10y agoFWIW it's very difficult to brick a calculator without doing so intentionally. The boot sector has a recovery mode built in for reflashing in case of the worst and the boot sector itself is write protected except in some very exceptional circumstances.
- qwertyuiop924 10y agoAh, good. Thanks Drew. By the way, I didn't see any actually, you know, graphing applications in the repos. Those exist, right?
- MaxLeiter 10y agoThey don't - KOS currently doesn't have FP support (although the C library[1] does provide FP, it's not too accurate or fast) [1] https://www.github.com/KnightOS/libc https://www.github.com/KnightOS/libc
- qwertyuiop924 10y agoFP?? I was asking about using the calculator as a calculator. EDIT: Oh, floating point! Now it makes sense!
- dalke 10y agoThere are a lot of used ones on eBay. The devices for all those graduated kids has to go somewhere. Looks like ~$20 for a TI-73, vs. $70 on Amazon, and ~$40 for a TI-83+, vs. ~$80 on Amazon.
- qwertyuiop924 10y agoAh. I always forget to check ebay. Although pre 84+ calculators were a pain to flash...
- hackcasual 10y agoWay back in the day I built a parallel port to 3.5mm jack flasher for my 83
- qwertyuiop924 10y agoYeah, but USB to 3.5 is a bit harder, IIRC...
- hackcasual 10y agoSurely arduino's these day would make that pretty simple
- qwertyuiop924 10y agoYeah, but I don't know how do do it :-(. I'm not so good at hardware...
- thesmallestcat 10y agoWow OP, this is a ton of amazing work (in the GitHub organization). Your blog is great too. Do you have any advice for being so prolific? My butt can't take the sitting and my shoulders can't take the typing posture for the amount of time it seems to take to churn out so much (not being sarcastic in the least).
- Sir_Cmpwn 10y agoThanks! I just spend a lot of time working. Maybe you can look into more novel keyboard designs and nicer or novel chairs? I use a mechanical keyboard with cherry MX blue switches and an above-average desk chair.
- thesmallestcat 10y agoThe above-average desk chair has made a huge difference but I've been using a cheapo keyboard for ages now, will have to get on that. Do you use a keyboard tray?
- Sir_Cmpwn 10y agoNo.
- niftich 10y agoAh, TI-83! I wrote my first-ever programs on this thing. The 'getting started with assembly' guide is really good; the whole thing is really inviting to tinker. Excellent work!
- boyce 10y agoAnyone looking to have a play without finding their TI link cable - works on Andiegraph TI emulator from F Droid
- tombert 10y agoThis deserves all the upvotes. You saved me a trip to eBay.
- overcast 10y agoI've still got my trusty TI-85 sitting next to me at the desk here, from twenty years ago!
- webkike 10y agoI dunno, the HP-50g was the pinnacle of calculator OSs for me. RPN, stack based programming, lisp. It really was wonderful.
- mveety 10y agoIt still is really wonderful! I use mine almost every day for little calculations I need to do. IMO a physical calculator beats using your computer as one in many cases.
- cathartes 10y agoI've long wanted to try the 50g, but haven't been able to forgive HP for ignoring longstanding bugs in the 35s and for outsourcing the design of the RPN calculators that they were rightfully renowned for. I ended up replacing my 35s with the "open source" WP 34s, which is based on the HP 30b calculator platform: https://sourceforge.net/projects/wp34s/ https://sourceforge.net/projects/wp34s/
- unixhero 10y agoWhy is RPN good? My gripe is: - Why should a person doing difficult mathematics also have to struggle with a different notation?
- kmill 10y agoBasically, when you're using a calculator, you're calculating, not notating. With RPN, you have a data stack, and everything you do is an action you perform on this stack (like entering a number or doing an operator). You can see your calculation in progress. It can be somewhat natural to put verbs at the end ("3 and 4's sum" for instance), and you don't have to think ahead to figure out whether you'll need parentheses. If the expression gets to complicated, though, traditional notation is nice because it's easier to verify you calculated what you intended to, I feel. But let me deconstruct your gripe. A good part of mathematics has been about finding the right notation to express particular ideas. RPN, in my experience, makes it easier to express certain calculations to a machine. But: why is there 'should' and 'have to' in your gripe? No one is forcing anyone to use RPN. You struggle with it to learn the notation, and maybe it makes the "difficult mathematics" easier to deal with. It's not like people make RPN calculators to be intentionally difficult and alien. Your gripe could equally apply to modern algebraic notation vs. the old latin longhand, or arabic numerals vs. roman. I'm sure it was a struggle for people to learn the new notation in either case.
- pg_is_a_butt 10y agoZShell or nothing.
- unixhero 10y agoNo install guide in the wiki. Humm.
- Sir_Cmpwn 10y agohttp://knightos.org/download http://knightos.org/download
- sleepychu 10y agoI'd never really considered this till now but all those "you must wipe the calculator's memory before the exam" rules are totally owned by installing a sufficiently deceptive custom OS. Like another commenter, I wrote some of my first programs on a TI-84, amazing that the school encouraged us to buy them and then completely failed to teach anyone how to use any of the features :'D
- vanderZwan 10y ago> that the school encouraged us to buy them and then completely failed to teach anyone how to use any of the features :'D This is exactly the kind of thing Seymour Papert warned against; just like handing out tablets and then stopping the students from learning how to unlock them for their own uses defeats the whole point.
- sleepychu 10y agoI don't think they actively tried to prevent it but I don't think they understood the power it contained. They were amazed when I showed them the in-built functions to solve many of the problems we were apparently learning to solve as well as the programs I wrote myself to automate tedious homework exercises.
- fimdomeio 10y agoI would say that for future hackers putting a calculator/tablet/whatever in one's hands and then trying to limit it's use just adds to the fun.
- vanderZwan 10y agoThat's good for finding the natural crypto people who like to break out of such crippleware restrictions, but I can't think of anywhere else in the industry where that is useful selection bias.
- eitland 10y agoSenior sysadmins? SW developers above CRUD level?
- linohh 10y agoWhen I was in school (10+ years ago) we already had elaborate mods for the TI83+ used for cheating our way through the final exams. Also we overclocked the hell out of them. Those were the days.