TGC

Episode 134 is Online.

Episode 134 of You Don't Know Flack tells the story of my pseudo Commodore 64 cracking group from the 1980s, the OK Krackers (OKK). (Listen to the episode to see why I used the word "pseudo".) In this rambling excuse for an episode I end up reminiscing quite a bit about the days of trading games over the modem through BBSes.

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Episode 134: http://podcast.robohara.com/?p=327
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Just a heads up Rob, it's taking a long time to dl from iTunes.

I too played a lot of the pirated games on my Atari 800 "Back in the day". I always wondered and still do, How did people break into the software and gain access to the game code itself?

RUP wrote:I too played a lot of the pirated games on my Atari 800 "Back in the day". I always wondered and still do, How did people break into the software and gain access to the game code itself?

http://en.wikipedia.org/wiki/Machine_language_monitor

One popular tool for the Atari 800 (in fit in the rarely used right cartridge slot) was "Monkey Wrench" that did exactly what obliterator said: monitor code in the left cartridge or what was in memory. Hackers also wrote program to read the code from the left cartridge.

In fact, one tool I used all the time was "The Pill". You use the code to scan the left cart and store it on a disk. Next you power off the Atari and replace the cart with a small white cart called "the Pill". That would simulate the operation of a regular cart and it would pull the scanned code from the disk and insert it in memory. It would trick the Atari into thinking it was running from a real cart instead of the pill. I had a couple dozen game program stored on floppies and played them regularly.

Dissasemblers were common tools. They would read the machine code from disk or memory and convert it to assembly code that the user could read. Some hackers - mostly for bragging rights - could read the machine code directly without a dissassembler.

Many hackers wrote their own tools but most simply downloaded them from various pirate BBS's out there (the old dial-in-with-a-modem kind).

ubikuberalles wrote: Some hackers - mostly for bragging rights - could read the machine code directly without a dissassembler.

There was a time when there were no assemblers so that was the only way to even write code. :D Of course, with a chip like the 6502, with less than 60 documented instructions, reading the machine code directly is just a matter of practice.

What's funny to me is that Jim Butterfield's seminal machine language book actually teaches you how to write some code without an assembler and just a monitor. Back in the day they taught you the low-level stuff before getting into high-level abstractions.

I always wanted to learn that stuff. How come they don't teach that in grade school?


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obliterator918 wrote:There was a time when there were no assemblers so that was the only way to even write code. :D Of course, with a chip like the 6502, with less than 60 documented instructions, reading the machine code directly is just a matter of practice.

I guess you could say I wrote machine language on my Dad's Altair and - later - on my Atari 400.

I wrote an editor program for the Altair just so I could write something on the Altair using a language other than BASIC. I got out a piece of paper and draw lines to make an assembler sheet, just like the sheets I used in college to write assembler for Motorola 6800 CPUs. I then hand wrote the assembler mnemonics (Branch labels, EQU statements and so on) and machine instructions (ROR, AND, BR etc) for my editor program.

The problem was, I didn't have an assembler for the Altair, and was stuck with a sheet full of words and symbols. The only thing I could do was convert the assembly code to machine instructions. In other words, I became the assembler. Much simpler than you would expect: I just substituted the machine commands with their equivalent numeric value. I had a spec sheet for the 8080a so it was simply a matter of looking up the code. After a while I was able to memorize the numeric code for a specific instruction.

Five years later I did the same thing for the Atari except the code I wrote then was much shorter - maybe 20-30 bytes long. I was too cheap to get an assembler and I already new the technique to do it by hand.

Writing the machine instructions without hand writing the assembly instructions first? Naw, I didn't do that, I wasn't that confident.

That's cool. It's becoming a lost art.

Unfortunately I'm with Aardvark. It's above me, I think. I mentioned in this episode that I watched over the shoulder of a guy manually cracking software in Assembly and that memory still resides with me. To me that was what a computer hacker really was; someone who understood computers on that level.

Not so lost as you think it is: http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/

AArdvark wrote:I always wanted to learn that stuff. How come they don't teach that in grade school?

Every kid in school should get an introduction to programming in Assembly.

In my opinion!!

I mean, it's not going to click with a lot of them. But think of all the time wasted in grade school or high school. You could do a lot worse and I think it's critical in understanding how computers work.

(I also think that electronic component comprehension ought to be a requirement as well. I never got that and to this day feel I missed out.)

they had a computer science class in high school but it really was 'intro to Basic'. I learned more on my C64 than the mono off brand IBMs they had. Christ, I never even learned how to format a floppy in school.


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Our school offered two computer classes. The first was a BASIC programming class on TRS-80 computers in the late 80s, when Apple, Commodore and IBM computers were everywhere. The other was called Business Computing (I took that one) and it consisted of 9 weeks of word processing, 9 weeks of spreadsheets, 9 weeks of databases, and 9 weeks of typing.

Enjoying this episode!
Ice Cream Jonsey: your avatar made me look up the whole backstory ;)

That is hilarious and ridiculous!