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Shhh: The Undocumented DOS Commands (1999)

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Re: Shhh: The Undocumented DOS Commands (1999)

#11

Post by daeken »

yjftsjthsd-h wrote: post #7

So how were these found? Today I guess I'd try running strings on the executable or maybe straight-up opening them in a debugger or disassembler (I assume command-line argument parsing is a very obvious, easy-ish to read block of code right at the start of the program), but I'm not sure how much of that was available (or at widely accessible, at least) back when DOS was a big deal (this list talks about DOS 2.x, whic…

debug.com shipped with the original MS-DOS and every subsequent version, so you automatically had a facility to disassemble and/or manipulate any running application essentially. We have easier tools now, but the tools available then were basically on every machine.

Re: Shhh: The Undocumented DOS Commands (1999)

#12

Post by pacaro »

yjftsjthsd-h wrote: post #7

So how were these found? Today I guess I'd try running strings on the executable or maybe straight-up opening them in a debugger or disassembler (I assume command-line argument parsing is a very obvious, easy-ish to read block of code right at the start of the program), but I'm not sure how much of that was available (or at widely accessible, at least) back when DOS was a big deal (this list talks about DOS 2.x, whic…

I remember using strings in the early 90s on DOS boxen, no recollection of where I got it from though, maybe a coverdisk, I could have implemented it myself, it's relatively trivial.

It's also worth remembering that DOS came with DEBUG, so if you had the time and patience you could dig about in anything

Re: Shhh: The Undocumented DOS Commands (1999)

#14

Post by wolco »

kirubakaran wrote: post #2

Back in the day there were several computer books in the r/The Undocumented .*/ pattern. That was super cool and I loved them, as if you were being revealed secrets that no one else knows. In retrospect they were mostly about unstable apis best avoided.

Great for exploit research.

With stable programs like DOS the hidden apis will be around awhile

Re: Shhh: The Undocumented DOS Commands (1999)

#16

Post by jhoechtl »

When you created an in-memory drive (what the heck was the name for them in DOS?), for example to store temporary files on, the label FDISKFAKE was automatically given. If you tried to format the drive, format complained that an in-memory drive can't be format. If you changed the label, format happily formated the drive.

Re: Shhh: The Undocumented DOS Commands (1999)

#17

Post by anigbrowl »

yjftsjthsd-h wrote: post #7

So how were these found? Today I guess I'd try running strings on the executable or maybe straight-up opening them in a debugger or disassembler (I assume command-line argument parsing is a very obvious, easy-ish to read block of code right at the start of the program), but I'm not sure how much of that was available (or at widely accessible, at least) back when DOS was a big deal (this list talks about DOS 2.x, whic…

Debug command.com

Re: Shhh: The Undocumented DOS Commands (1999)

#18

Post by anigbrowl »

Exmoor wrote: post #3

>Last updated on Friday, January 1, 1999. This is a walk down memory lane, but not in a good way. I'm very, very glad to no longer have to remember anything about config.sys.

But I bet you do, including how to create it on a system with no editor.

Re: Shhh: The Undocumented DOS Commands (1999)

#19

Post by dialamac »

jhoechtl wrote: post #16

When you created an in-memory drive (what the heck was the name for them in DOS?), for example to store temporary files on, the label FDISKFAKE was automatically given. If you tried to format the drive, format complained that an in-memory drive can't be format. If you changed the label, format happily formated the drive.

RAM drive? Ramdrive.sys
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