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Back in 1993, I was taking a number theory class

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Re: Back in 1993, I was taking a number theory class

#151

Post by wave100 »

QuinnWilton wrote: post #31
chungy wrote: post #29

Earlier quoted context omitted.

Doesn't seem extremely effective unless you also remove the F2, F10, Shift, and Alt keys from the keyboard.

Oh and it wasn't. That was the least of the school's problems though. They also used a surveillance system called LanSchool, which sent out all of its commands entirely unencrypted and unauthenticated, so people would spoof the remote takeover command and steal exams from teachers' accounts. It ended up being a whole thing my senior year.

This thread is making me remember how incompetent my old school district used to be with technology. Once upon a time, a friend of mine got detention for opening a command line and running `tree`. The teacher said that he was hacking the computer.

The name of the class? "Digital literacy".

Re: Back in 1993, I was taking a number theory class

#152

Post by a3n »

kqr wrote: post #150
a3n wrote: post #146

Earlier quoted context omitted.

> I would like to politely contest the authenticity of this specific detail. > People's natural mental sorting algorithm is most often insertion sort. [embarrassed panic] [trip down wikipedia lane] No, it was bubble sort. Data and loop management for insertion sort wouldn't have been something I would have thought of back then.

What confuses me is that isn't the data and loop management for bubble sort even more complicated? Insertion sort is literally just "keep track of the index beyond the last sorted element, then scan for the next smallest element and swap it in, repeat until you have gone through the entire array." This is about as simple as a comparison sort gets. (And it's what literally everyone I've watched does when they get deal…

But you're speaking from knowledge and analysis. I only had the perspective at the time of looking at the world through a paper towel roll. Anyway, it was the first idea that bubbled up for me.

Re: Back in 1993, I was taking a number theory class

#153

Post by twic »

amenghra wrote: post #33
thaumaturgy wrote: post #32

Ah yes, good memories. I'm having a really hard time right now remembering the name of that program that blocked access to the Finder; I think it was "Easy"-something. Google fails me on the name too. Breaking it was a hobby. Some school labs had left access to Hypercard available through that program, so you could just pull up Hypercard and make a new stack that would tell the program to quit. The other way to get a…

AtEase?

Ah, i thought they were talking about MiniFinder:

https://apple.fandom.com/wiki/MiniFinder

https://winworldpc.com/screenshot/c29050e2-809c-c2a3-24e2-80...

But that was a bit earlier.

From what i remember, MiniFinder was written for MFS, and did not support hierarchical directories. You couldn't use applications unless they were at a filesystem root.

Re: Back in 1993, I was taking a number theory class

#154

Post by kqr »

someguyorother wrote: post #149
kqr wrote: post #130

Earlier quoted context omitted.

It sounds like you essentially invented the spreadsheet. Nice work! > Part of the calculation involved sorting. I didn't know anything about sorting, so I implemented what I later learned was bubble sort. Because that's obviously how you'd do that. I would like to politely contest the authenticity of this specific detail. In my fairly strong collection of evidence, people just do not bubble sort without being told ho…

> I would like to politely contest the authenticity of this specific detail. In my fairly strong collection of evidence, people just do not bubble sort without being told how to do that. FWIW, my first sort was selection sort. "Find the smallest element, place it at the start, repeat" seems like the obvious way to do it, without the fussing about with shuffling already sorted elements out of the way that insertion so…

I just now realised that when I talked about insertion sort I really meant selection sort. How embarrassing of me to lecture others and then go on to make such a basic mistake myself!

Re: Back in 1993, I was taking a number theory class

#155

Post by someguyorother »

DyslexicAtheist wrote: post #136
elengyel wrote: post #19

I'd like to clarify that my code was running only on machines that were otherwise idle. Not many people were in the lab late in the evenings. MPQS processing nodes could be added and removed dynamically, so if somebody needed a computer that was part of my cluster, they could just quit my program and everything would go back to normal. Also, once the number theory professor learned of what I had implemented, he worke…

what a wild story. the first thing that came to my mind reading through wasn't a picture of a modern Mac but of TempleOS. It's amazing how we study computing changed since then as in we're focusing more on learning about all the required plumbing and duct tape than the actual machines. Not that this isn't fun too but it has essentially shifted everything. Getting into "mainstream" computers back then was such a diffe…

You can also get some of the same near-the-machine fun by going into security. Shellcode has to be short and close to the OS, and breaking the stack (stringing together gadgets, and so on) by its nature subverts the higher abstraction layers.

Re: Back in 1993, I was taking a number theory class

#156

Post by DyslexicAtheist »

eru wrote: post #140
DyslexicAtheist wrote: post #136

Earlier quoted context omitted.

what a wild story. the first thing that came to my mind reading through wasn't a picture of a modern Mac but of TempleOS. It's amazing how we study computing changed since then as in we're focusing more on learning about all the required plumbing and duct tape than the actual machines. Not that this isn't fun too but it has essentially shifted everything. Getting into "mainstream" computers back then was such a diffe…

Almost the same lament could have been written in the 1990s in nostalgia for the glory days of the 1960s.

I was neither idealizing nor being nostalgically "lamenting", but thanks for the negativity. I was merely pointing out the differences in how "the getting results in X" has moved up the stack.

Re: Back in 1993, I was taking a number theory class

#157

Post by wheybags »

TchoBeer wrote: post #97
wheybags wrote: post #89

I did a nasty hack a little like this when I was in college. College wired internet had all sorts of filters on it, I can't remember the details exactly. The important thing was it didn't allow the upd ports for counter strike from the wired connection we had in a society room. The computer science department had their own web proxy, which was only accessible from inside their network. Cs students could SSH into spec…

Was running counterstrike through two computers really faster than just using the wireless connection or did that one have weird filters too?

WiFi was crap, wired we could pretty much saturate our gigabit NICs. And WiFi had similar, but different filters iirc.

Re: Back in 1993, I was taking a number theory class

#158

Post by sampo »

From around 1996-1997, when Linux desktop use became popular, some university departments had this distributed computing system installed in both classroom computers and staff's desktop computers, to run distributed computing jobs when the computers were not in use otherwise.

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

Re: Back in 1993, I was taking a number theory class

#159

Post by DonHopkins »

kqr wrote: post #130
a3n wrote: post #45

In 19 and 82 or 3, I worked at Lockheed Shipyard in Seattle, in a sort of tech writing capacity on a Navy ship building project, based on my recent experience in the Navy. The business closed with completion of the ships. We had to fill out lots of forms that documented what we called "analysis," and we'd often have to change them based on some factor changing. One change could cascade through the whole form. Paper f…

It sounds like you essentially invented the spreadsheet. Nice work! > Part of the calculation involved sorting. I didn't know anything about sorting, so I implemented what I later learned was bubble sort. Because that's obviously how you'd do that. I would like to politely contest the authenticity of this specific detail. In my fairly strong collection of evidence, people just do not bubble sort without being told ho…

Bubble sort is just fine if you're sure you'll only have a few items, or if it's likely that it might already be sorted, but it's still embarrassing admitting implementing it. Even Barack Obama knows that!

https://en.wikipedia.org/wiki/Bubble_sort#Performance

>The only significant advantage that bubble sort has over most other algorithms, even quicksort, but not insertion sort, is that the ability to detect that the list is sorted efficiently is built into the algorithm. When the list is already sorted (best-case), the complexity of bubble sort is only O(n). By contrast, most other algorithms, even those with better average-case complexity, perform their entire sorting process on the set and thus are more complex. However, not only does insertion sort share this advantage, but it also performs better on a list that is substantially sorted (having a small number of inversions). Additionally, if this behavior is desired, it can be trivially added to any other algorithm by checking the list before the algorithm runs.

>In popular culture: In 2007, former Google CEO Eric Schmidt asked then-presidential candidate Barack Obama during an interview about the best way to sort one million integers; Obama paused for a moment and replied "I think the bubble sort would be the wrong way to go."

Here's an implementation of bubble sort written in PostScript by Sam Leffler, renowned BSD/Lucasfilm/Pixar/SGI/Alias/Softimage/VMWare hacker, which he sent me and gave me permission to distribute in 1988, but which he was too embarrassed to sign his own name to, so he used the pseudonym "Bobo Leffler".

https://donhopkins.com/home/archive/psiber/cyber/bubblesort....

https://en.wikipedia.org/wiki/Samuel_J._Leffler

Also here's a PostScript heap sort by Owen Densmore of Sun, and a PostScript insertion sort by John Warnock of Adobe, both of whom used their real names:

https://donhopkins.com/home/archive/psiber/cyber/heapsort.ps

https://donhopkins.com/home/archive/psiber/cyber/insertion-s...

Re: Back in 1993, I was taking a number theory class

#160

Post by eru »

DyslexicAtheist wrote: post #156
eru wrote: post #140

Earlier quoted context omitted.

Almost the same lament could have been written in the 1990s in nostalgia for the glory days of the 1960s.

I was neither idealizing nor being nostalgically "lamenting", but thanks for the negativity. I was merely pointing out the differences in how "the getting results in X" has moved up the stack.

Sorry, I wasn't trying to be negative.

Yes, things have moved up the stack. And so have they done in the 30 years before the 90s, too.

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