Ask Slashdot: What Are Some Things That Every Hacker Once Knew? (ibiblio.org) 615
Open source guru Eric Raymond turns 60 this year, prompting this question from an anonymous reader:
Eric Raymond's newest writing project is "Things Every Hacker Once Knew," inspired by the day he learned that not every programmer today's knows the bit structure of ASCII. "I didn't write it as a nostalgia trip -- I don't miss underpowered computers, primitive tools, and tiny low-resolution displays... In any kind of craft or profession, I think knowing the way things used to be done, and the issues those who came before you struggled with, is quite properly a source of pride and wisdom. It gives you a useful kind of perspective on today's challenges."
He writes later that it's to "assist retrospective understanding by younger hackers so they can make sense of the fossils and survivals still embedded in current technology." It's focusing on ASCII and "related technologies" like hardware terminals, modems and RS-232. ("This is lore that was at one time near-universal and is no longer.") Sections include "UUCP and BBSes, the forgotten pre-Internets" and "The strange afterlife of the Hayes smartmodem" (which points out some AT commands survived to this day in smartphones). He requests any would-be contributors to remember that "I'm trying to describe common knowledge at the time." This got my thinking -- what are some that every programmer once knew that have since been forgotten by newer generations of programmers?
Eric Raymond is still hard at work today on the NTPsec project -- a secure, hardened, and improved implementation of Network Time Protocol -- and he promises donations to his Patreon page will help fund it. But what things do you remember that were commonplace knowledge "back in the day" that have now become largely forgotten? Leave your best answers in the comments. What are some things that every hacker once knew?
He writes later that it's to "assist retrospective understanding by younger hackers so they can make sense of the fossils and survivals still embedded in current technology." It's focusing on ASCII and "related technologies" like hardware terminals, modems and RS-232. ("This is lore that was at one time near-universal and is no longer.") Sections include "UUCP and BBSes, the forgotten pre-Internets" and "The strange afterlife of the Hayes smartmodem" (which points out some AT commands survived to this day in smartphones). He requests any would-be contributors to remember that "I'm trying to describe common knowledge at the time." This got my thinking -- what are some that every programmer once knew that have since been forgotten by newer generations of programmers?
Eric Raymond is still hard at work today on the NTPsec project -- a secure, hardened, and improved implementation of Network Time Protocol -- and he promises donations to his Patreon page will help fund it. But what things do you remember that were commonplace knowledge "back in the day" that have now become largely forgotten? Leave your best answers in the comments. What are some things that every hacker once knew?
Handmade Hero (Score:5, Interesting)
Watch Casey Muratori's Handmade Hero, where he codes a game live on Twitch from scratch with no 3rd party libraries.
His entire effort is fueled by his desire to educate the next generation of developers with an understanding of how computers *actually* work, which is something he feels is both important and has been lost.
https://handmadehero.org/ [handmadehero.org]
Big Floppy is scamming you (Score:5, Interesting)
Stick a hot soldering iron through the upper-left hand corner of your 720K floppy and now you've doubled the capacity.
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Stick a hot soldering iron through the upper-left hand corner of your 720K floppy and now you've doubled the capacity.
there was alot of floppy tricks. !!! i remember on old apples there was a special hole puncher to make the disk double-sided (on the apple you had to flip the disk but ibm could read both sides).
also there was 3rd party software on both platforms to format the disks to all sorts of strange/larger capacities. i remember os/2 warp 3-something shipped on like 30 3.5 floppies that were formatted out to something like 1.7mb (xdf??) - but anywhat, ppl. expanded this and there were dos drivers that could format a
Hole punchers for old floppies (Score:4, Insightful)
i remember on old apples there was a special hole puncher to make the disk double-sided (on the apple you had to flip the disk but ibm could read both sides).
You didn't need a special hole puncher. A regular round hole puncher worked fine and I did this routinely. If you wanted nice square notches an exacto knife would do the job. You only bought the "special" disk notching hole puncher for showing off.
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I'm pretty certain it wasn't the travel range of the head that was the problem but the variable spindle speed used in by their GCR format on 400k & 800k disks.
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Big Floppy
There's a pill for that.
Re:Big Floppy is scamming you (Score:5, Funny)
There wasn't one then.
EBCDIC (Score:4)
Specifically, EBCDIC-ASCII tables.
Re: EBCDIC (Score:2)
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Sending EBCDIC data on half inch tapes.... those were the days...
Re:EBCDIC (Score:5, Insightful)
For some of us, it's today... I have two processes where the data arrives as EBCDIC plus binary data, and the files are constructed to emulate a 200-byte tape record. I got to learn all about how COBOL represented numbers in various fields to get these running in 1991 and 2000, and still have to remember them when the people source the data need help remembering how it works.
They keep saying they want to sunset the applications that generate the EBCDIC data, but, in 15 years of saying that, they have yet to create a viable alternative.
Pinouts (Score:5, Interesting)
RS232 an null-modems are mentioned in TFA, but I'd like to add a detail:
Most of the more hackerish students where I went (ca 1990) knew the minimal pinout for a null-modem by heart so we could improvise one with 3 wires and matches/paperclips/whatever. By the time we graduated LANs and to some degree internet mane that knowledge obsolete, but it sure did save the day a few times, typically for transferring files between different platforms with different floppy formatting.
Re:Pinouts (Score:5, Interesting)
Eh, networking multiple Amigas together at a copy-party...
Nobody had any special hardware. But we had a bunch of serial and parallel cables, and every Amiga had a serial and a parallel port. So we'd daisy chain them serial-parallel-serial-parallel...
Then there was no real networking software, but there was the contents of the computer connected over serial or parallel seen as an extra "disk drive" with its volumes seen as directories.
So, you want to copy a file to that guy three computers over to your left? The guy to your left connects to you over serial, so open the 'drive' that stands for serial link, and you're on his computer. Then open the 'parport' directory and you're two computers over. Open another 'serial' and you're with access to the computer you wanted :D
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Yes, you are right, I'd use pin 7 as well. Using case ground wasn't the right way to make the cable but because 1 was shorted to signal ground 7 it would still work, mostly. Yeah, I remember cts/dts and dsr, for hardware handshaking.
That the only way to (Score:3)
repetitively assure a V.32bis connection was to use a US Robotics modem and all the cloned softmodems were garbage.
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Soft modems were garbage, no doubt. But Rockwell still made some amazing modem chipsets. A lot of people forget that K56Flex (Rockwell's proprietary 57,600 bps encoding) could actually get to 56k on phone lines due to superior error correction, where USR's proprietary version topped at 53,000. When the V.90 standard came out, it used the lesser encoding and topped at 53,000; the Rockwell V.90 modem chipsets would still do K56Flex if you configured them to with your initialization string (AT commands, woo
Hexadecimal (Score:5, Funny)
Hexadecimal: what it is, why it is and how & why it evolved from octal.
That, and why real computer scientists often confuse Halloween w/ Christmas: 31 Oct = 25 Dec.
Re:Hexadecimal (Score:5, Insightful)
Hexadecimal: what it is, why it is and how & why it evolved from octal.
This word 'evolved'. I don't think it means what you think it means.
Multiples of 4 bits (ie. hexadecimal) is more natural in a binary world.
Multiples of 3 is stupid, it was only ever going to be temporary.
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chmod 755 a.out
chmod 644 foo.txt
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which lives on to this day in *nix
chmod 777
chmod uses octal numbering, one bit for each flag, and the flags are in groups of 3.
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Considering there's one digit per 'entity' they might just as well be hexadecimal with top bits of each digit unused.
Download resumes (Score:3)
Only had a chance with Zmodem.
DOS Hackers (Score:5, Interesting)
(Yes, they existed - especially in the mid-1980s) all knew:
- Interrupt 18 to force a reboot
- The memory range which was set aside for the display, and which you had to write to in order to do graphics (non-hackers used libraries but hackers mostly went for embedded assembler to try and squeeze a little more speed out for graphics work)
- The hex number for every one of the 16 colors a CGA display could show (Sierra Online took it a step further in the AGI engine and invented an early precursor of the scene-bumpmap which allowed their pseudo-3D adventure games to work by using a map-image where depth was indicated by color allowing characters to walk in front or behind objects). Unlike a true bumpmap it didn't specify height for lighting, it specified distance from the screen for movement. It allowed the Y axis to double as a Z axis
- How to read/write from the parallel port
- How to write to the PC-speaker's memory address to play sounds
- How to access extended memory
All things that went by the wayside when Unix and Win32 became available on the PC platform, acting like you are root all the time became frowned upon, libraries became the normal way of doing things, memory wasn't artificially limited to 640K. Some of the legacies of this era lived on rather longer than you'd think. As late as the early 2000's the best way to run most games on Linux was still using SVGALib - which wrote directly to video memory and didn't require resources for X, but in an age before the DRM driver in the kernel SVALib meant you had to run your game as root. I still played Quake2 that way ! The way SVGALib worked was simply a slightly larger memory region using the exact same techniques that we had used in the 1980s.
Re:DOS Hackers (Score:4, Insightful)
The memory range which was set aside for the display, and which you had to write to in order to do graphics (non-hackers used libraries but hackers mostly went for embedded assembler to try and squeeze a little more speed out for graphics work)
My primary reason for disliking Win 95 was it was the first Windows OS which started to really mess with programs that wrote directly to the memory address A0000000 for graphics. I was only a hobbyist in high school at the time and had a hard time finding an alternative which performed as well as TASM code writing directly to the hardware. Eventually I started using DirectX but I remember having a real hard time finding information on how to use version 1.0 in late 1995. I relied heavily on Lamothe's "Tricks of the Game-Programming Gurus" to learn these techniques at the time, and wasn't skilled enough yet to learn new technologies quickly on my own.
Re:DOS Hackers (Score:4, Interesting)
And interrupt 27h to terminate stay resident :) The fun we used to have with that one in my school PC labs...
Re:DOS Hackers (Score:5, Interesting)
Indeed, and back then parallel was significantly faster than serial (hence it being used for printers). It was a favorite tool for copying files between PC's as well as it could do in 20minutes what would take an hour over serial (after a previous hour trying to get both PC's serial ports configured to matching configurations).
Among the hacker crowd it had another major use too - you had 8 circuits that could be individually switched on/off by sending a different byte over the port, It was extremely low voltage (you could just about light-up an indicator LED with it - but you could use it to flip a switch, whether that was an electronic transistor based on or a cheap relay-based one depended on your budget) and that meant you could turn non-computer devices on and off with software.
The early days of home-automation relied on the parallel port because a single CPU in the box could control 8 different devices and switch on any particular combination of them at any given time. It didn't become possible to do that over a serial port until the other side of the connection was smart and could actually execute instruction code.
In my case - I had a complicated circuit that replaced the controller of a scalectric car with 4 voltage boosters allowing step-up speed control (all off would stop it), and the other 4 bits on the other track. So sending 10001000 would have both cars drive at minimum speed, 11001000 would have the first car at twice the speed of the other.
Then I started the process of trying to program a time based sequence to give me perfect (fully automated) scalectric laps with no cars ever flipping but doing the track at the highest speed possible. It would have been so glorious...
Would have been...
See I was about 12, my electronics skills were not that advanced and frankly I hadn't considered the huge amount of RF noise that scalectric brushes produce - let alone that slowing down caused the motor to act as a generator creating voltage the other way (the same effect now used for regenerative braking in Tesla's)... a mere few hours after I got the whole thing to work... I fried my motherboard. And that, ladies and gentleman, is the story of how I learned the value of surge protection. That too is something every hacker (at least those in lightning territory) used to know - modems on phone lines had a nasty habit of sending lightning surges through your PC.
You soon learned that surge protectors had limited power against the kind of voltages lightning strikes put on a line... you always unplugged everything at the first sign of a cumulonimbus cloud.
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Yes, it was a BASIC command... It's become short hand, at least around here, for writing a value to memory space in any language, at least around here. I guess it's like "googling" or "grepping", just a handy verb.
I never did much with DOS beyond QuickBASIC because that's all I had. I was mostly doing Amiga stuff in assembler and Blitz BASIC. Blitz was great because it handles all the boring set-up and file loading, but allowed you to write in-line assembler for the performance critical parts.
The Amiga was
old school (Score:3)
8N1 ;^)
ATH
Acoustic Couplers
DSDD
Floppy notcher
HAM (not radio)
The Turbo button is not always your friend
Green vs Amber, the eternal war
8-bit Bucket List: TWO floppy drives!
I'm old.
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And insulting somebody, writing "you are an idi^H^H^H misguided"...
Paai
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The word "ham" in "ham radio" is not an acronym. ...de K5ZC
Re:old school (Score:4, Funny)
Don't forget modems that didn't have guard time between +++ and actually entering command mode.
There was a good amount of time when you could get on IRC or something similar and type +++ATH and watch 1/3 of the channel disappear because they hadn't updated their firmware, or had a shitty modem that couldn't update firmware to fix it.
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Hardware Hackers. (Score:2)
The original hackers were of course Hardware Hackers. Long before software was a thing (in the hobby world).
Most were ham enthusiasts, but HiFi and RC modelling was also popular.
There was even a shop called "The Hardware Hacker" long before the term became pejorative.
What Are Some Things That Every Hacker Once Knew? (Score:5, Informative)
What Are Some Things That Every Hacker Once Knew?
Do you mean hacker as in programmer or hacker as the media usis it to describe a digital burlgar? If you mean the former, these days it seems to be simple stuff like checking for open ports with telnet and then having fun by typing in protocol messages: http://www.shellhacks.com/en/S... [shellhacks.com], or even simpler stuff like editing documents with vi and using command line programming tools. These used to be things that every programmer knew, I learned this in school but many of our new recruits seem to be totally unaware of this stuff. I've written programs tens of thousands of lines long with nothing but vi, gcc/g++, make, tcpdump+Wireshark, valgrind, vi and a few other choice commandline monsters but these days the GUI generation seems to need a GUI editor, preferably a GUI IDE, a GUI networking tool, a GUI debugger, etc... to do simple stuff. I don't usually even need a debugger, I can normally figure out what is wrong without one. A few years ago I was handed a .NET assignment. After much complainign and whining (Unix guy through and through) I coded it up using that primitive little Windows CMD terminal, a freely available .NET compiler and vi/make before the IT department got around to installing Visual Studio. The really funny thing was that even some seasoned .NET developers were surprised to see you could (a) run vi/make and other GNU tools on Windows and (b) compile .NET code from the command line: https://msdn.microsoft.com/en-... [microsoft.com]. BTW, and this is probably heresy around here, but I really like how Microsoft seems to have a well documented API for everything as long as you are willing to bother learning .NET or Visual Basic.
Re:What Are Some Things That Every Hacker Once Kne (Score:4, Informative)
Do you mean hacker as in programmer or hacker as the media usis it to describe a digital burlgar?
It's an ESR article. Eric never uses the word "hacker" in the latter sense.
Old vs common use of word "hacker" (Score:4, Insightful)
It's an ESR article. Eric never uses the word "hacker" in the latter sense.
This is true. He keeps fighting that fight looooong after it has been lost. Nobody outside of a few pedantic geeks (like many of us here) use the word hacker in the positive sense ESR insists it should mean.
Re:Old vs common use of word "hacker" (Score:4, Insightful)
Geez, what's going on at all those "hackathons" then?
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Personally, I find most IDEs unusable compared to the CLI tools. They tend to be laggy and crashy and at the same time unable to handle some fairly simple things that vi handles easily. They also seem to have no way to handle anything vaguely 'special' in the build process.
It might be easier to use the CLI tools while wearing mittens than it is to use an IDE.
Why DEL is 0x7F (Score:5, Informative)
The "control characters" have their own special position in ASCII, as the codes below the space character: 0x00 through 0x1F.
Yet, for some reason, there is one more sort-of control character outside that range: DEL, which is 0x7F. This bit of lore is actually from before my time, but I know why.
People used to actually use paper-punch machines to punch input tapes. What could you do if you mis-punched? There's no good way to fill in holes you didn't mean to punch, but you could go back and punch more holes. ASCII is a 7-bit standard and DEL is all 7 bits set. So, if you hit the wrong key on the punch, you could hit DEL and it would punch out all the rest of the holes, making 0x7F or DEL, and the paper tape reader would simply ignore any DEL characters it saw.
Oh, I guess anyone who can use Wikipedia didn't need me to find this [wikipedia.org] out.
P.S. I didn't actually know why the carat notation for DEL is ^?, but Wikipedia explains that [wikipedia.org] as well. Neat!
Old codes I remember using (Score:5, Insightful)
Epson printer ESC codes - you embedded them in text documents and sent them to your parallel port dot-matrix printer, and they produced bold and italics and double width, and all sorts of effects.
ANSI escape screen codes - for setting foreground and background colours and other screen effects (clear screen, home) when you got bored with light grey on black.
Overlays (Score:4, Interesting)
Every hacker over a certain age knows what is meant by the term "overlay", from minicomputers to CP/M to MS-DOS. And it fills them with dread to this day.
The crucial prompt: term? (Score:5, Interesting)
Where I went to college, there were dumb terminals hooked up to serial lines in various locations around campus. Students would take turns using them. (They're all gone now... everyone has their own computers and it's all WiFi and/or Ethernet now.)
When you logged in to any campus computer, the very first thing it would do was print a cryptic prompt: term? [vt100]
This was your one opportunity to correctly enter a terse code that described the terminal you happened to be using. Terminals were not cheap, and nobody was going to throw away old ones when new ones were bought, so the campus had a mix of terminal types. It would have been nice if there had been a universal standard way to interrogate a terminal to find out its type (some reserved escape sequence) but there wasn't, so it was up to you to enter it correctly.
So every terminal had a little slip of paper on it saying something like: TERMINAL TYPE: vt100
There was always a default, which you would get if you just hit the Enter key. I cheated in the above examples and put vt100 but I think the default was something else; VT-100 terminals were not actually common (I think I only ever saw one!). I no longer remember what was common, just whatever they happened to buy a lot of.
If you got it right, then the system used termcap [wikipedia.org] to look up the capabilities of your terminal, and it would know how to use the cursor-movement features of your terminal. In short, you could run programs like vi and emacs. If you got it wrong, and then tried to run vi and emacs, your screen would become horrible hash quickly. What on one terminal would move the cursor around might be meaningless on another terminal or might have some different effect. (Imagine if the "move cursor to X,Y" command one one terminal was "clear to end of line from position X,Y" on another brand of terminal. That sort of wackiness.)
So the two bits of lore that every computer-using student at my college needed to know: how to correctly enter the terminal type, and how to fix it if you entered it incorrectly. (Best to just stop what you were trying to do and logout!)
But here's the punchline of the above lore:
Computer geeks like me used the terminals all the time. People who had to do statistics work also used them a lot, but some students rarely used them. For some students, the only times they used a terminal was once per quarter, to sign up for classes for the new quarter.
When I started at college, this was easy. You got a paper printed class catalog booklet, you would look up the course numbers of the courses you wanted to take, and from any terminal you would login to a special account. A program would run, reading standard input and writing standard output, and it would prompt you to enter your student ID number and the course numbers. After you entered each number, you would be prompted: Is this correct? yes/no and you would answer. Simple. I don't think it even bothered to prompt for terminal type, and even if it did, it didn't use it for anything.
But then some computer science grad students went ahead and improved the system. They added browsable menus. You could use the arrow keys to browse through, drill down, find your course and pick it. You didn't need a paper catalog of course numbers! But now you actually needed to enter the terminal type correctly. All the students who rarely used the terminals had no clue what term? [vt100] meant, and usually just hit Enter, and then they were hosed.
I'm sure now it's all web forms: no need to print paper booklets, and nobody has any serious problems using it. Not all the old ways were better.
P.S. The campus had a couple of ADM-3A [wikipedia.org] terminals, and I used them from time to time if nothing better was available. They had no dedicated cursor arrow keys, but had arrows printed on H J K L pointing left, down, up, and ri
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Serial (Score:4, Interesting)
9600,8,N,1,XON/XOFF
DB9:pins 2/3/5
DB25: pins 2/3/7
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Interesting. What was reading the other end?
Yeah, serial still comes in handy for mobile phone stuff I'm finding since learning you can trigger some mobile phone headphone jacks to be serial ports. I want to deep dive into android soon so I suspect that I'll be brushing the dust off my memory of the stty command. I was so happy that knowledge I thought of as obsolete, was again new, funny how old knowledge comes back around to you in IT, eventually.
I remember when I started out, making a massive bundle o
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Or the modern equivalent:
White orange, orange, white green, blue, white blue, green, white brown, brown.
Yes I know this is different in the USA.
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You forgot "tab down," which caused a lot of confusion when training a coworker (and not specifying that) once. But only once...
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9600,8,N,1,XON/XOFF
I remember there was a startup ISP in my area that was looking for beta testers before they were ready for paying customers. They put a small ad in the local newspaper that simply stated their dialup number, followed by 9600,8,N,1.
Use Netcat to send an email (Score:4, Insightful)
The security implications these youngsters miss should keep everyone awake at night.
old school? (Score:5, Interesting)
I'm seeing a plethora of 6, 5 and even 4 digit userids post here for this one. Good to see we ain't dead yet...
WDD1100 jumpers, ABit dual CPU mobos w/ peltior plates.
My Yellow card, Abend Aid was an amazing help when looking at 40Meg bal360 dumps.
Trips over to the data center to nail down the last couple slashes for some JCL
Late afternoon games of snipes on Novell 2.15 networks
Using that 3270 terminal/XT PC in my cubical farm nest - SNA and IPX/SPX
programming the Gigi keyboards to mess with others in the college computer labs
replacing miles of coax with Cat5 as a sign of the change of times.
Now I get to sit on the porch here in sunny south Georgia and chat with other old timers. TV studio eng, Packet radio guy,
and so many others. The poor kids of today don't really understand how good we had it.
SCSI Voodoo (Score:2)
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A real cool thing about a SCSI chain is that you could have several drives shared between several computers. A friend had an Amiga, Sun and PC all on the same bus with a few drives. There was even a program on the Amiga that could pretend to be a block SCSI device made up of parts of others disks.
I once ran a name server that would boot from a disk that was shared and maintained by another system. Named was run by init after the network setup stuff had run. The right signals on the serial line and bind w
Ob (Score:3)
How to design a usable GUI.
fixed point numbers (Score:2)
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Floppy disks drilling & punching holes (Score:2)
5.25" single-sided floppies could be converted into double-sided disks,
by punching or cutting a marker hole in the right place.
Drilling a hole in 3.5" DD floppies would double their density to HD.
I assume this trick worked due to laws of mass production.
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If you didn't use Apple II or Commodore, you also had to cut an index hole. This was considerably more complicated. I eventually would just slip something protective into the disk and slash out a square with a razor blade. Then repeat for the other side.
And, for what it's worth, you can't read the other side with a double-sided drive for two reasons. The obvious one is that the track spins backwards (as if that would stop a dedicated Catweasel user), but the less obvious one is that the second side is offs
UUCP (Score:2)
Yeah, I remember spending a lot of time getting my head around UUCP and uuencode. Once I did it made my life so much easier not having to have work come to a halt while a modem transferred a file or running a remote command getting the clients machine to do all the calling to save my phone bills.
uucp made a really good bridge that was really hard to hack. Setup to access an outside system via a serial line a one way UUCP out and no TCP/IP connection to certain core systems, a cracker would have to spawn a g
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Booting computers with switches (Score:3)
Loading the initial software on these kinds of systems often required setting the console switches to a specific pattern. On some of the early minicomputers the operator had to use the toggle switches to load a short binary program that would be the first stage of the boot sequence. Sometimes the next stage was loading a more complex boot code that was input from paper tape. Even with a disk attached the load sequence was power up the machine into a non-running state, toggle the low level boot into memory, load the paper tape, then press a button to start the machine. If it all went well the result was a prompt on the console TTY or VDT accompanied by a bell (TTY) or a beep (VDT).
The console switches could be read and the lights set in software. Sitting at the machine console an experienced operator could tell how busy the computer was by looking at the light pattern. In some desperate circumstances code could only be debugged by having test code that read the switches and set the lights as it ran.
In George Lukas's first full length move THX 1138 there is an IBM 7094 mainframe. It had lights that formed a grid that could hold a few letters. At one key point in the film just before the end, these lights spell the word "TILT".
Some numeric values and basic concepts (Score:4, Insightful)
8 bits can store +-127, 16 bits can store +-32,767 (OK: add 1 to the absolute for negative numbers). 32 bits can store +-2,000,000,000 (well, a bit more), 3600 seconds in an hour, 86400 seconds in a day.
I find that some programmers only have a hazy idea what is meant by a 32 bit or 64 bit machine. These are fundamental, but they somehow get jobs not knowing the basics.
MVS core dumps (Score:2)
Reading a core dump on a System 390 (running MVS / OS/390 / etc) machine.
It's 3.00 am and the program has crashed after running for 6 hours. You can't re-run it, you have to find out why it crashed, fix it, and checkpoint-restart to completion. You have until 5.00 am. Your time starts now. Oh - and it's PL/I. An infinite loop in an IMS/DB program. Be afraid.
The ONLY information you have is the core dump, the program listing (albeit with object map), the linker map, and maybe - if you're lucky - a DB du
Realigning the head of a datasette (Score:2)
Fourth edition of Hackers Dictionary? (Score:3, Insightful)
As far as I know the third and last edition of the Hackers Dictionary stams from 1996. I certainly hope that this all leads to a new and long overdue edition...
Paai
Assembly Language, (Score:3)
I taught myself Basic on the TRS80, and into Assembly Language, I've always been a pirate (TRS80 had very little, I was making up for it), Amiga came out and I went that route, the Basic was so bad I had to quit or toss the system, and Assembly language is what I've forgotten, I knew it at 286, more registers than I know of now.
Debugging Code by Inspection (Score:3)
Reading code in order to detect bugs/issues because the compile/run cycle took hours. Seems to be a forgotten art now days.
Kermit (Score:5, Insightful)
The protocol, not the frog (which it was named after).
lower your phone bill (Score:3)
by using PC Pursuit to call BBSes.
Or just use the modem at work and lie about it when the phone bill comes in.
Getting annoyed when some salesrep starts sending a fax when you're in the middle of an important zmodem download on the same phoneline.
POSTSCRIPT is a programming language. (Score:5, Interesting)
Nobody remembers this. Postscript printers? Oh, well, just another driver from the list. Postscript files? Oh, just another format to store text or graphics.
I needed to make a rotary quadrature encoder of a specific number of pulses per rotation. I took the gap encoder (like these found in ball mice) and needed a disk with the right number of gaps. With gap width of order of 0.3mm. How to get that? Oh well, I'll have a transparency printed with the pattern.
Now... how to generate such a pattern? If I try raster graphics, I'll need enormous file to get the resolution I need. It will take a lot of time to generate. Well, maybe write it in Postscript?
Some search, some learning, and soon I had the postscript file, maybe 500 bytes long., with a bunch of code discs of various diameter and various number of cycles. Packed it onto a pendrive, took it to a print shop and asked to have it printed.
"It's half a kilobyte. Are you sure this is the right file?"
"Yeah, just import it into your graphics program."
"uh... okay." The file loads, the guy scrolls through two pages of of extremely detailed patterns. "Is that it?"
"Yeah. Print it on transparency, at as high DPI as you can."
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Anyone remember Don Lancaster's tinaja quests and Postscript contests? [tinaja.com]
call backs (Score:3)
I forgot how I did this, but at work I set up the server where from home I would login to it with kermit and I would do something. The the remote server would call my system back were I could get in without having my phone # billed. At the time I was running Coherent 286.
IBM and more (Score:5, Interesting)
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Or, if you're lazy, 'man ascii' (in Linux)
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i'm always wondering: wouldn't a modern compiler also catch that and do it for you?
so you just end up making more complex code to read just to manually do an optimization the compiler would do for you anyway.
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Re:bitwise math (Score:5, Informative)
In .NET, no. About 6 years ago I was tasked with rewriting our base-64 encoder/decoder. We were using MS's built-in encoder and is was too slow to handle a multi-GB inbox (we sold a shrink-wrap email server for ISP's). First I rewrote it in regular math operations, and it was faster, but not fast enough. I rewrote it again using bit-shifting operations and it was an order of magnitude faster. I really had to reach back into my days coding MUD's in C for that. We really take our faster computers for granted, and our code is far from the level of optimization we were once required to achieve.
Re:bitwise math (Score:4, Insightful)
We really take our faster computers for granted, and our code is far from the level of optimization we were once required to achieve.
And that's a good thing too; now we can focus on more important things. It also makes our code better in terms of readability and maintainability. I once had to optimize the crap out of a routing algorithm to bring the execution time within acceptable limits. I made it work within the time allowed, but the resulting code was extraordinarily hard to understand and maintain. On better hardware we got away with a straight-up, clean implementation in C.
But knowing weird ways to optimize code still comes in handy from time to time. I know programmers who manage to squeeze a couple of ms from a routine and turn a sluggish bit of UI into something that performs smoothly. And I see others who give up thinking "this is as good as it'll get".
Re:bitwise math (Score:5, Interesting)
For signed numbers, >> 2 and / 4 are not the same operation, so the compiler cannot do it for you.
Of course it can.
Compilers aren't AI, they can do any 'trick' the compiler writer knows, eg. using a shift instruction that preserves the sign bit. You need to disassemble some compiler output sometime and see the impressive amount of tricks they know. It's almost as if the compiler writers take pride in their work.
Re:bitwise math (Score:5, Informative)
Ahh yes the good old days of XOR-based linked lists [wikipedia.org].
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It's fair to say that not every hacker knew this. Those of us who grew up with 8-bit micros in the 80s were either Z80 or 6502 (the COSMAC was very rare), and those who used one didn't use the other.
I was 6502, so I know what you're talking about.
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and those who used one didn't use the other.
Everybody knew both where I worked and we all moved the 68000 with no problems. All it takes it 10 minutes looking at clock cycles in the back of the manual.
Re:Zero Page memory locations (Score:4, Insightful)
*Bzzzzt* thank you for playing!
I had various Z80 and 6502 based machines (eg MZ80K, ZX Spectrum, BBC Micro). The BBC's OS was a thing of beauty!
And now all this time later I'm working with a microcontroller (ATMega328P) which for my purposes has much the same performance at ~1MIP (though on as little as microamps rather than an amp or so), but with nice hardware multiply and GPIO!
Rgds
Damon
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Re:Zero Page memory locations (Score:5, Informative)
The zero page on e.g., a 6502 consisted of the first 256 bytes in memory, so the address of any byte therein was only a single byte in stead of two. Access therefore was faster on that page than of all other parts of memory.
The Apple II was my first computer. I bought it when I was thirty, in 1979. I then was an art historian, looking for new ways to administrate art collections. It really changed my life
Paai
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Hi 73 here. First program at University using Fortran and punched cards. Still know and remember 90% of the ASCII character table in my head. Use the ASCII sort procedures to this day in some of my file names to force them to come to the top of a file list.
Spent a lot of time learning the HP Printer control procedures in the early 90's and became quite proficient programming HP printers. Learned quite a bit about the Hayes modem command set. Experimented a lot on Centronics printer interfaces and RS232. I
Re:Every hacker once knew? (Score:5, Insightful)
I worked in a building numbered 2600 with a bunch of developers for a few years. One day I pointed at the massive street numbers on the side of the building and said something like, "How appropriate." None of them had any idea what I was talking about.
Most kids these days have no idea what phreaking is, what a black box is, or a blue box, etc... [wikipedia.org] Don't get me started on the contents of the anarchist's cookbook.
Most of them don't know what a MUD, MUSH or MUX [wikipedia.org] was or how to program one, let alone about common door games (Trade Wars [wikipedia.org] was the best).
Heck, I remember key cards which worked by perforations. Really easy to duplicate with a piece of cardboard. Remember core memory? Many "technical" folks nowadays probably can't do Boolean logic and wouldn't recognize most of the symbols. let alone binary operations or PEEK'ing and POKE'ing.
Thanks guys, now I'm starting to feel old. :)
Re:Every hacker once knew? (Score:4, Interesting)
Ah... 80 column punch cards. And walking down the stairs with a 20 cm stack of data plus program, and dropping them, and then having to sort them by hand...
Paai
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Use the -d flag with pkunzip, otherwise, you might end up with a big stinking mess.
Why was this not the default?
ZIP files are still screwed. Do you want to "Extract here" or "Extract to archive.zip\".
Either you will clutter up your downloads folder in a similar "big stinking mess", or else you will end up with "archive.zip\archive\archive\files.exe"
Why can it not be smart enough to figure out if there's a parent sub-dir in the archive before creating nested redundant sub-dirs.
Re:Always (Score:4, Interesting)
Use the -d flag with pkunzip, otherwise, you might end up with a big stinking mess.
Why was this not the default?
Probably because CP/M didn't have directories, and PKZIP had a definite familial relationship with LBR, which came from CP/M and therefore had no directories; and with ARC, which was cross-platform, including a CP/M port.
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I used to know a good part of the dos/pc memory map, and before that certain 8-bit micros.
Yes, you youngsters had it easy...
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were awesome necause Tandy looked better than the PCClones. They. yended to be passive cooled processors and thuds quieterr as compares to the bulky beige PC/Clone.
There was a magazine called TRS80 and it would have programs you could input. I'd spend 6 or more hours inputting them with cassette storage lots of peeking and poking.
Re:Ugly things from the eighties! (Score:4, Interesting)
IBM Series M keyboards.
TeamOS/2. These was one of the scenes you hung out in, if you wanted to be a PC-hacker.
Tag Lines: eg OS/2: because a 386 is a terrible thing to waste. or OS/2: a multi-threaded suite.
AT (and other pretentious terms that dated just too quickly).
Floppies (of all sizes).
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Firewire DMA, which can be used to snag the encryption key for various DRM schemes (though you usually don't have to go to such lengths). There are
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Hey! The IBM 3270 was excellent! As was the 3290!
Re:Old skool goodies (Score:4, Informative)
FIDO.
Email delivery in single-digit days was shockingly cool.
ASCII pr0n.
Dial strings to coax another .5k baud out of that Hayes clone.