A cheeky intern nearly turned MS-DOS into NSFW-DOS
- Reference: 1712574012
- News link: https://www.theregister.co.uk/2024/04/08/ms_dos_easter_egg/
- Source link:
At the end of a [1]video in which former Microsoft engineer Dave Plummer attempts to explain the workings of the [2]xz backdoor and how it came to be, a nugget was dropped about an Easter egg that almost made it into MS-DOS. It is not a backdoor but a cautionary tale regarding checked-in code and the benefits of code reviews.
Plummer's story goes back to 1993, the final days of MS-DOS. He was an intern at the time, tasked with working on the disk compression technology in version 6.2 of the operating system. He shared an office with another intern who clearly had too much time on his hands.
[3]
"He was working on the copy command," explained Plummer, "and he took the opportunity to check in – not a backdoor per se – but a special command line switch."
[4]
[5]
A command line switch is something familiar to many a console jockey and is used to modify or set a parameter for a given command. For example, adding /s to the end of an [6]xcopy command will copy all folders and subfolders, except empty ones.
[7]How a single buck bought bragging rights in the battle to port Windows 95 to NT
[8]Windows Format dialog waited decades for UI revamp that never came
[9]Plummer talks to us about spending Microsoft's money on a red Corvette
[10]USB Cart of Death: The wheeled scourge that drove Windows devs to despair
In this case, Dave's fellow intern decided to do something special. "With copy he added it so that /♥ ... would just print 'I love sex' over and over and over."
Plummer had no idea about the change until he received a terse call from his manager at home. The switch had been caught (presumably in a code review) and management was not amused.
He was asked: "What did you know about this?"
[11]
The honest answer was that he knew nothing.
"Naturally," said Plummer, "they did not invite the guy back."
"It did not look good for him. I don't know what the repercussions were; I don't know what they did. All I know is that they took me at my word that I wasn't involved."
[12]
Plummer wound up working for Microsoft for years afterward but admitted: "I don't know if I would have hired me after that little incident in my office … Did I really not know about it? No. I didn't."
Plummer told The Register : "It would be more precise to say that he TRIED to sneak it into the copy command, but it was caught. I'm not privy to the HOW part, though.
"I know for sure it never made it into a release build." ®
Get our [13]Tech Resources
[1] https://youtu.be/uRlxN0_zVHo?si=221KW137ixFWDrqX
[2] https://www.theregister.com/2024/04/01/xz_backdoor_open_source/
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZhQUnK7PW82K8pazhEoepgAAAIY&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZhQUnK7PW82K8pazhEoepgAAAIY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZhQUnK7PW82K8pazhEoepgAAAIY&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://learn.microsoft.com/en-us/troubleshoot/windows-client/installing-updates-features-roles/switches-with-xcopy-and-xcopy32-command
[7] https://www.theregister.com/2024/03/28/plummer_windows_95_nt/
[8] https://www.theregister.com/2024/03/27/windows_format_dialog_temporary/
[9] https://www.theregister.com/2024/03/08/spending_microsoft_money_on_a/
[10] https://www.theregister.com/2023/11/25/windows_usb_cart_of_death/
[11] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZhQUnK7PW82K8pazhEoepgAAAIY&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[12] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/oses&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZhQUnK7PW82K8pazhEoepgAAAIY&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[13] https://whitepapers.theregister.com/
Re: This is fairly common...
I'm no expert, but I would imagine that if the government wanted to send someone to undertake some covert act, they'd provide better some better cover/backstory than that they "used to work for the government".
Re: This is fairly common...
Keep it close to the truth - the more outlandish your lie the more detail you have to remember about it
So you say something like "I was a civil servant" which usually shuts most people up, if they push further then you could say you were an administrative officer in the department of Agriculture or the Scottish Office or Work and Pensions or something equally boring. Much easier to remember as a cover story than "I worked for McDonalds as a fish descaler" when that process is automated or "I was a yacht salesman in Oxford" when it's miles inland.
Re: This is fairly common...
I worked for an organisation who employed someone who was siphoning money out to a well known 1970s sectarian terrorist organisation. We only found out about that years later when they were convicted for their crimes.
It was quite a reminder that you don't always know those you work with, drink with, socialise with.
Re: This is fairly common...
"worked for the Government"
A lot of people have thought that after looking at their tax deducions.
"... 1993, the final days of MS-DOS ..."
Hardly. Windows ME was released in 2000, and was still just a graphical shell on top of MS-DOS.
I assume they meant the era when DOS as a standalone entity was still a significant concern/product in its own right.
DOS 6.22 was the last vesion of MS DOS released, in 1994
MS DOS 6 was released in 1993, and 6.1 in Sep 1993
So the article is correct
WEin95 DOS SHELL returned V7 as a version, but this was never released as a standalone DOS.
It wasn't released as a standaline product, but it was fairly easy to extract the DOS element from W95 and run it on an older machine which didn't support the W95 GUI, as I recall!
Indeed so. I had many a DOS7 boot diskette for all those time a clean boot was required.
Simpler times.
Yes, I remember spending simple evenings trying various TSRs orders to get the magical amount of those 640KiB free so that whatever game would deign to start, while still keeping the mouse and disk caching and XMS or EMS available, whatever the devs had decided they wanted to use. Loads of fun, it was.
Technically IBM PC-DOS 6.1. There wasn't an MS-DOS with that number.
"I know for sure it never made it into a release build."
If "I love sex" was denied release in 1993, that means Microsoft Edge had a 22-year development cycle.
Double negative?
"Did I really not know about it? No. I didn't."
So, he's admitting that he DID know about it? He didn't not know about it.
Re: He didn't not know about it.
It's not necessarily a binary choice here: "didn't not know about it" also covers cases like "I had an idea he might try something of the sort", or "I thought he was joking when he told me", or "I knew he'd written that, but assumed he wasn't so stupid as to actually commit it", &etc.
Re: Double negative?
To me, a question has the same meaning whether it's worded affirmatively or negatively, so I always ignore negatives, I think it makes answers less confusing:
"Didn't you know?" => "No, I really didn't know" or "Actually, yes, I did know"
Anyhow, it's better for Plummer to say he didn't know. This may make him look negligent, but the alternative is that
1) he knew about it and was stupid enough to let this code be submitted
2) he then didn't take responsibility and threw his intern under the bus when asked if he was aware
Got the t shirt
We routinely adjusted the dos command interpreter output strings for our own entertainment. Most of it much more nsfw then this example ha ha
Don't recall that getting into the wild though thankfully...
Three copy commands
If at first you don't succeed, leave it the bugs there and then do it all over again only this time with different problems.
Re: Three copy commands
That's the standard recipe for re-writing software...
The good old days
When MS did code reviews, and spotted undesirable changes before the product shipped...
Re: The good old days
As much as it hurts to defend MS, doing a code review for a product that fits on a floppy disc or two is a tad simpler than doing a code review for the behemoth Windows has grown into.
The lack of pre-release testing however is indefensible.
Did dos even have a ♥ character?
Yes. https://en.wikipedia.org/wiki/Code_page_437
(I remembered it having some awful graphic character nonsense, had to check about that specific character. But it was there.)
Comes from Extended ASCII from IBM.
"He was working on the copy command," explained Plummer
It explains an awful lot about the quality of MS operating systems if something as majorly important as the copy command was left to Beavis and Butthead to implement.
Re: "He was working on the copy command," explained Plummer
It also explains why it was caught; They didn't trust interns so checked the code more closely.
Re: "He was working on the copy command," explained Plummer
As opposed to now, where interns run the house.
This is fairly common...
A lot of large companies hire a lot of people. We had one guy who came in for a month, having previously "worked for the Government" who quit after a couple of months. Very suspicious, but we found nothing untoward.
Who knows? We got some good work out of him at least!