Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

I found a 55 year old bug in the first Lunar Lander game

martincmartin.com

Post reply on HN
Print view View original

31–40 of 124 posts

Re: I found a 55 year old bug in the first Lunar Lander game

#31

Post by lucb1e »

Viliam1234 wrote: post #21
kelsey98765431 wrote: post #10

[flagged]

I agree with you in abstract, but uMatrix solved this problem for me. Also, it's funny how people often say "the stupid cookie banners are there because of GDPR", but actually GDPR requires that the Reject button be as large and as easy to click as the Accept button, and somehow most companies do not care about this part. (Also, GDPR does not require a cookie banner when your website does not place cookies. Seriously…

> GDPR does not require a cookie banner when your website does not place cookies

You can place cookies and not need a cookie banner.

You just can't use consent as a legal basis when you haven't yet asked for consent, that's the only thing all these websites are doing: no legitimate reason for the invasive tracking they want to do and thus they're legally obliged to ask you in a clear way if you will consent to it.

If the data processing were to fall under a reason such as:

- in order to fulfill a contract (such as your visitor asking the website to log them in)

- or a legitimate interest (murky, but aggregated statistics like setting returnVisitor=true should fall under this)

- or one of the other reasons defined in GDPR (I think there are three more besides consent, like public interest, vital interest of the subject, and one more I forgot)

then you don't need to ask for consent to process this data or, specifically in this case, place this cookie.

Re: I found a 55 year old bug in the first Lunar Lander game

#32

Post by martincmartin »

jprete wrote: post #24
martincmartin wrote: post #9

Earlier quoted context omitted.

OP here. One interesting thing about FOCAL is that * has higher precedence than /. So in Lunar Lander, M*G/Z*K is what mathematicians and other languages would write M*G/(Z*K). I did a double take when I first saw that. :) As the Wikipedia article says, "This can cause subtle errors when converting FOCAL source code to other systems." Also, the IF syntax is a little limiting and hard to read, although I suppose progr…

That's surprising from today's perspective, but when I imagine the thought process, it seems reasonable, especially for math and science purposes where multiplication and division operators usually get grouped into a series of multiplications above the division bar, and a series of multiplications below it.

True. + also has higher precedence than -, so that a - b + c means a - (b + c).

Re: I found a 55 year old bug in the first Lunar Lander game

#33

Post by [deleted] »

coldpie wrote: post #30
kelsey98765431 wrote: post #10

[flagged]

You don't need to put up with cookie banners. Enable the Cookie Notices and Annoyances filters in your uBlock Origin installation, and consider setting up a Kill Sticky bookmarklet[1]. [1] https://www.smokingonabike.com/2024/01/20/take-back-your-web...

[deleted]

Re: I found a 55 year old bug in the first Lunar Lander game

#35

Post by schiffern » 

  >The rocket equation is what gives rise to the suicide burn being optimal
Nitpick, but this isn't strictly true.

Even if you don't count the vehicle getting lighter as it burns fuel (which is all the rocket equation does here), a suicide burn will still be optimal.

The real reason is because a suicide burn minimizes gravity loss.

https://en.wikipedia.org/wiki/Gravity_loss

Re: I found a 55 year old bug in the first Lunar Lander game

#36

Post by sema4hacker »

In the mid 70's I wrote a 2D vector graphics moon lander game for the Adage graphics terminal. You came in fast horizontally and had to use push buttons for the LEM side thrusters and main engine to slow down and land horizontally, resulting in either a crater if you were too fast, or if you ran out of fuel, otherwise you saw one or more planted American flags depending on the quality of the landing.

Years ago I threw out my only copy of the source code, thinking it had no value and would never be re-used, something I regretted later when I realized how early a graphics game it was historically, and how easily it could have beeen resurrected with a simple emulation.

Re: I found a 55 year old bug in the first Lunar Lander game

#37

Post by dadadad100 »

lionkor wrote: post #17
luxuryballs wrote: post #8

I wonder if this works for braking in automobiles to minimize brake pad wear.

Automobiles are more (wear-)efficient at braking when they use the engine to brake, not the brakes, so that would probably be a better approach to automate

A long time ago, in a book whose title I don’t remember, a character said, “but engine parts are more expensive than brake parts”. That has always stuck with me, even as I glide to a stop with almost no braking.

Re: I found a 55 year old bug in the first Lunar Lander game

#38

Post by bee_rider »

layer8 wrote: post #26
realslimjd wrote: post #6

Earlier quoted context omitted.

There were on the order of hundreds of high school students with computer access in the US in 1969, and even fewer with computer literacy. Growing up in the Space Age probably was inspirational, but that doesn't change the fact that computers basically didn't exist to the general public at that time. Unlike now, software development wasn't a widely known career. There wasn't a CS major in the US until 1962. I think t…

It’s unsurprising that at least one of the hundreds would write such a game though? In particular when those having access already are self-selected to some degree.

It’s unsurprising that anything was done by somebody. In fact it is inevitable that the most impressive thing is done by somebody out there, because otherwise it wouldn’t be a thing that was done. But, being that person can still be impressive.

Re: I found a 55 year old bug in the first Lunar Lander game

#39

Post by ljf »

dadadad100 wrote: post #37
lionkor wrote: post #17

Earlier quoted context omitted.

Automobiles are more (wear-)efficient at braking when they use the engine to brake, not the brakes, so that would probably be a better approach to automate

A long time ago, in a book whose title I don’t remember, a character said, “but engine parts are more expensive than brake parts”. That has always stuck with me, even as I glide to a stop with almost no braking.

Very true - but I drive cars until they die - and have never had a car issue because of engine braking - it is usually another part of the car that goes before whatever damage I am adding to the engine, becomes an issue. So engine brake away!

Re: I found a 55 year old bug in the first Lunar Lander game

#40

Post by martincmartin »

schiffern wrote: post #35

>The rocket equation is what gives rise to the suicide burn being optimal Nitpick, but this isn't strictly true. Even if you don't count the vehicle getting lighter as it burns fuel (which is all the rocket equation does here), a suicide burn will still be optimal. The real reason is because a suicide burn minimizes gravity loss. https://en.wikipedia.org/wiki/Gravity_loss

OP here. True, I oversimplified. What I meant was, there are two parts to the dynamics, the rocket equation and gravity. They add linearly, so any extra velocity that comes from gravity needs to be eliminated by increasing the delta V from the rocket equation. The gravity delta V is just acceleration of gravity times time, so you want to minimize the time. Surprisingly (to me), in the rocket equation, it doesn't matter how long it takes, or what sequence of burns you use, or whether you burn at a constant rate all the way through vs short strong bursts, etc. So to land with zero velocity using the least fuel, you just need to land in the shortest amount of time.
Post reply on HN