The message text limit for the Marquee screen saver is 255, even if you bypass the dialog box that prevents you from entering more than 255 characters

If you find an old Windows XP machine and fire up the configuration dialog for the Marquee screen saver, you'll see that the text field for entering the message won't let you type more than 255 characters. That's because the Marquee screen saver uses a 255-character buffer to hold the message, and the dialog box figure there's no point in letting you type in a message longer than the screen saver can display.

A customer decided to bypass the configuration dialog and change the text in the screen saver by editing the settings directly, and then complained that the Marquee screen saver truncated the message at 255 characters.

Well, yeah, because the limit is 255 characters. That's what the dialog box was trying to tell you. If you bypass the dialog box and whack the setting directly, that doesn't change the Marquee screen saver. Its limit is still 255 characters.

It's like attaching a gizmo to the gas pump fuel nozzle to disable the auto-stop feature because you want to put 20 gallons of gas into your 15-gallon tank. Disabling the auto-stop will not make the gas tank any bigger. All it does it make it easier to accidentally overflow your gas tank's buffer.

Comments (49)
  1. pcooper says:

    I love your analogies.

  2. Danny Moules says:

    With hilariously darwinian results.

  3. Joshua says:

    Bypassing GUIs and writing configuration directly is a good way to exercise untested code paths.

  4. Eoin OC says:

    @Joshua – Sure it is if you're involved in the development of the application in some way. But not so much if you're just an end user.

  5. Joshua Ganes says:

    Cool, I didn't know my gas tank had a buffer. Fuel tank overruns are one of the biggest security holes in gas stations today. If you overwrite your stack pointer with an appropriately lit match, a fireball virus can infect the whole station.

  6. Matthew W. Jackson says:

    Tell the customer that it does work. They just missed the important step of patching the executable to increase the size of the buffer.

  7. Pink Duck says:

    I'd like to know what kind of message the customer was trying to display that requires someone to wait while more than 255 characters scrolls past.

  8. Pink Duck says:

    I'd like to know what kind of message the customer was trying to display that would require someone to wait while more than 255 characters scroll by in front of them.

  9. Mark (The Other Mark) says:

    I wonder if the customer now has a Twitter account.

  10. Why did the screen saver have a 255-character static buffer?  That seems a little low.

    Kudos to the customer for trying to solve the problem themselves before calling support, though.

    [Low? This isn't a news ticker. It's a freakin' marquee screen saver. 255 characters won't even fit on the screen all at once! -Raymond]
  11. Timothy Byrd says:

    [Low? This isn't a news ticker. It's a freakin' marquee screen saver. 255 characters won't even fit on the screen all at once! -Raymond]

    I have to admit I find your indignation entertaining, Raymond.

    Kudos to the programmer for writing the screen saver to successfully resist that black-hat's marquee overrun attack, though.

  12. Danny says:

    "If you find an old Windows XP machine…"  -What's this? Ray's snarky comment? lol, the message I'm writing this is a XP machine..and I bet is still the most used OS, hence Micro$oft 2 times increased the year when they will stop support it. Sorry Ray, your beloved Vista/7 still suxx…oh, sorry, lemme rephrase that..Vista/7 suxx more then XP, which after 3 patches started to suck less. When you'll sweat 3 patches on 7 then I'll agree with you on "old" word above.

  13. David Maher says:

    @Danny Windows XP was released back in 2001. I'd say an operating system from almost a decade ago can safely be classified as "old".

  14. dave says:

    Ha, ha. He spelled "Microsoft" with a dollar sign. What a funny and original joke!

  15. James Schend says:

    Now I kind of want to write a screensaver that marquees the entire text of Moby Dick– and keeps track of where it left off so it can start there next time.

  16. Andreas Rejbrand says:

    For one, I really love the Microsoft Windows 7 operating system, and think it is great in (almost) every way. [And I haven't used Windows XP since the release of Vista.] Also, I am not alone; indeed, Windows 7 seems to be the most commonly used OS in Sweden, according to

  17. db2 says:

    "[Low? This isn't a news ticker. It's a freakin' marquee screen saver. 255 characters won't even fit on the screen all at once! -Raymond]"

    If the text had to all fit on the screen, then there wouldn't be much point in having it scroll, now would there?

    [I think people have lost sight of what the original Marquee screen saver was used for. It was for showing a brief message of maybe two or three words. It wasn't for displaying long running text. I mean, look how dorky it is! -Raymond]
  18. Burak KALAYCI says:

    "If you find an old Windows XP machine" is an unfortunate expression, not something – a casual expression- you'd expect to hear from a programmer, especially from somebody like Raymond. People still use XP on their newest computers. I do.

    Seven is OK. But Vista!?!! That really sucked. Remember it couldn't even copy files properly. And remember it sucked so much that Vista 1.1 is called Seven, MS had to drop the name (And remember XP had SP2 rather than a name change).

    [Would everybody be happy if I removed the word "old"? So much kerfuffle over one lousy word. -Raymond]
  19. c says:

    @Matthew the problem is that someone might actually try to patch the executable.

  20. DWalker says:

    Danny, you're being rude.  "your beloved Vista/7 still suxx"?  It's not entirely Raymond's product; he didn't create the products, and he regularly points out the parts that are not well done.  I don't think all of Vista and 7 are "beloved" by everyone, including many Microsoft programmers.  

    I suspect the opinions within Microsoft about Vista and 7 are vastly different, although outsiders seem to forget that Vista was MUCH better by the time the second service pack came out.

    Feel free not to use Vista or 7 if you don't like them.  And you spelled "than" wrong, along with other grammatical errors and missing words.  :-)

  21. Danny is correct that Windows XP is the most common OS in use, with almost twice the market share of Windows 7.…/Usage_share_of_operating_systems

    As of December 2010

    Windows XP (44.0%)

    Windows 7 (24.23%)

    Windows Vista (16.74%)

    Mac OS X (6.82%)

    iOS (iPhone) (1.94%)

    Linux (1.53%)

  22. Crescens2k says:


    That list is made up of the identifying string of web browsers and how often they frequent websites. So it isn't worth much.

    But you also have to recognise two points here. First, XP is probably staying in use for businesses because of inhouse software which they use and it doesn't work on anything but XP or IE6. So they are pretty much forced. On the other hand, according to this list, 7 has a 24% share after around a year of general sale. So what will it be like next December?

    Burak KALAYCI:

    You seem to be happy in your ignorance here. Because don't forget Windows XP is Windows 2000 1.1 (which didn't suck at all) and they superceeded XP with 1.2 (Server 2003). So if you use your logic correctly here, XP sucked so much they renamed it to 2003. Also when they updated MCE and released the x64 version of XP, they used 5.2 (the Server 2003 version) not 5.1 (original XP version) so that would mean that the original XP sucked too right?

    Of course, that is utterly stupid. What people forget that Vista was a MAJOR rewrite. That is why it got a new major version (6.0) Do you remember the breakage that Windows NT 4 had, or Windows 2000 had? I remember taking a look at NT 4 in the early days and I couldn't run it, after a couple of minutes running on my system it would blue screen. But this was after NT 3.51 which was pretty stable. Then 2000 came along, by this time they had some major fixes out for NT 4 and it was running very stable, but 2000 had major launch issues too. So Vista having launch issues and requiring more time to settle (at least one service pack, the same for all other versions) is no surprise. To be honest, I would much prefer Vista SP2 over XP SP3 any day.

  23. Burak KALAYCI says:


    You clearly misunderstood my 'OS renaming logic'.

    Ah, yes I remember NT 4 with pretty Win 95 interface. And I had a similar blue screen experience, but the reason turned out to be a faulty RAM module on our monster Pentium Pro 200 MHz server.


    [Would everybody be happy if I removed the word "old"? So much kerfuffle over one lousy word. -Raymond]

    I would. But I guess it's too late now.

  24. Rofl says:

    My new favorite game is guessing what the worst comments will be about.  For this article I predicted criticizing the screensaver for using a small fixed-size buffer, and complaining about the HTML marquee tag.

    So that's a hit, a miss, and a complete failure to realise that all posts that name any specific version of Windows will quickly degenerate into the usual tedious Vista-bashing.

  25. Dean Harding says:

    @Burak KALAYCI: Old is old. XP is 10 years old this year, that's old. Just because people are still using it doesn't change the fact that it's old. My car is old, just because I'm still driving it (and it works fine for me!) doesn't mean it's magically "new".

  26. Cheong says:

    @dave: That remind$ me of the old joke that involve$ $tudent $ending letter to hi$ parent with word$ typing like thi$ $entence. XD

    That leaves reasonable doubt that the real reason he don't move to Win7/Vista is because of $$$…

  27. lefty says:

    Well, if nothing else, the nitpicking here seems to have identified the fabled "???" variable in the steps to profit.

    It used to be:

    1) read "The Old New Thing"

    2) ???

    3) Profit!

    Now we know that step 2 is:

    > Create a new, improved Marquee Screensaver that accepts an unbounded amount of text for Windows XP!

    Whoever might decide to do this, please send the royalty checks to – I'll be sure to cut Raymond in on his share.

  28. Cheong says:

    @lefty: Actually I've more prefer to have the text stored as double null terminated string, so I can keep strings displayed in green keep running down the screen… I could even use putty to capture some lines in "make bzImage" to make myself looks cool.

  29. Duke of New York says:

    This is clearly Microsoft's fault for declaring a buffer slightly shorter than MAX_PATH. Every dev knows that a buffer MAX_PATH characters long can magically hold anything.

  30. GWO says:

    <blockquote>If you find an old Windows XP machine …</blockquote> Does this not work on new Windows XP machines?

  31. Neil says:

    @Crescens2k: Business-level Windows 7 includes Windows XP mode. I've used it to run Removable Storage against a remote server.

  32. Burak KALAYCI says:

    @Dean Harding:

    Yes, XP might be considered old and, how we appreciate it more as it gets older, just like some good wine. Just like the IBM Model M keyboard made in 1995 I'm typing on right now, some things are old and still awesome.

    Nothing is wrong with 'old'. Just because it is old does not mean it is less awesome.

    But as GWO pointed out, and I said, it needn't be found only on old machines. I buy my new computer to run good old XP, just like many others.

    I may drive an old (maybe a classic) car, that doesn't imply I should drive it on old worn out roads…

  33. …. worst comments … complaining about the HTML marquee tag.

    I'll be happy to oblige.

    First I must note that the <marquee> tag isn't really HTML at all, it's an Internet Explorer-only extension which emulates… you guessed it… a news ticker.

    Re: getting 255 characters on the screen at the same: I have so far been able to resist the temptation to install XP, set a large screen resolution, a small font size, and set a string with a bunch of combining characters.

    But what is the original customer's scenario – what (longer-than-255-character) string do they want to pass to the marquee screen saver?  Is there a better way that meets their needs?

  34. Random832 says:

    "Just like the IBM Model M keyboard made in 1995 I'm typing on right now" – I hate to nitpick, but if your Model M keyboard was made in 1995, it's not IBM.

  35. doug.kavendek says:

    I vote that the next windows version be named Windows Kerfuffle.

    Also, everyone offended by 'old' up there is just looking for a fight.  I still like XP more than 7 after using it for a year, but there's a point where you need to decide what things are worth making a fuss over.  And how can anyone think that a blog post about the marquee screensaver is an appropriate place for that?  Sheesh!

  36. Burak KALAYCI says:


    My blue label was made by Lexmark for IBM but it has IBM branding, if it's not IBM, then what it is? (not that the brand really matters. If someone makes the exact same keyboard, that keyboard will be as awesome as mine).

  37. Anonymous Coward says:

    We use Win7 at work and that's pretty much convinced me to keep my XP machine as long as possible. Maybe it's all better under the hood. Heck, I bet it is. But the user interface is a major step backwards in terms of usability.

  38. Andreas Rejbrand says:

    @Anonymous: That is highly subjective. I think the Windows 7 GUI is the most beautiful GUI I have ever seen (together with the Media Center GUI), and I also find it highly efficient. When I use a XP computer today (happens once a year ore something), I always mess things up by typing Win + some phrase + Enter! And when I use a Windows Vista PC, I keep trying to use Win+1 to start the web browser, Win+2 to start Outlook, etc. Not to mention the nice window management features of Windows 7 (Win+arrow keys, snap to edge, etc.). However, there is one thing I miss from Windows Vista. In Vista it was very easy to group/sort the files in a folder according to different criteria (last modified/file type/date recorded/author/…). You just had to use the header. In Windows 7, the header is invisible unless you select report view.

  39. Dean Harding says:

    @Burak KALAYCI: Sure, but nobody said old == bad.

  40. Burak KALAYCI says:

    @Dean Harding:

    So I guess we agree that XP is the best OS ever written, which is now 'old', just like your car :)

    Remember how the best feature in Windows Seven was seen (by many) as the 'XP mode'. (I don't think this is true, I'd use VPC2007, but this was the case).

    Remember how MS provided confusingly named downgrade rights to upgrade from Vista to XP.

    Remember how some Chinese pirates whined that they made a loss with their Vista sales.

    My point is: XP is still loved and used, so one should not expect to find it only on 'old' hardware.

    Windows Seven is OK. I truly hope next version of Windows will be even better. And with 64 bit migration, XP will continue to live in our hearts and virtual machines (still on new hardware).

    @Andreas Rejbrand:

    Incidentally my awesome Model M keyboard does not have a Windows key…

  41. Crescens2k says:

    Well, regardless whether XP is seen as "old" or old, the only reason why I have had to use Windows XP recently was because I had to reinstall a 5 year old PC.

    Otherwise I have not had to touch XP ever since I moved to Vista after SP1 was released except for the programs that initially had major problems because they did really stupid things that only worked on XP.

    Older games etc which use weird copy protections which installed drivers are run on 32 bit Windows 7. My normal usage is on 64 bit Windows 7. This was the same with Vista and has worked perfectly well since 2008.

    This following bit is only my opinion but for most people I know who still use XP it seems to be a mix between not wanting to spend money on the newer versions, or not wanting to relearn things, (or are so old fasioned that they dont thing "new fangled things" add anything). There are probably a fair few who got put off with the inital problems with Vista RTM (like the file copy problem that was mentioned) but a good majority of these problems, and the speed issues were fixed with SP1. But of course, a bad image would remain. I am also sure that a lot of the stats for XP users come from Asian users, especially Chinese and they are well known for pirating. It has become a lot harder to pirate Vista/7 so they are sticking at XP.

    Another issue here is the whole thing of support vs innovation. Newer Windows features like Direct2D, transaction support etc are great features, hell even with the people hating it, DWM was a great addition. Also, again it was hated because it added a bit more complexity, but session 0 isolation was also another great addition for security. But you have to consider carefully whether you want to use them at all. This is because you would end up having to support more and people would see this as having to do more work than necessary.

    In the end though, people are going to like it, others are going to hate it, this is life. I would personally say right now 7 is the best operating system available. If you ask Linux fanboys they would burn you at the stake for thinking anything Windows related could be classed as "The best operating system ever". So as with all things, the "best" operating system is purely opinion. So the best thing to do is everyone who likes XP keep living with it, those who like newer versions would keep living with what they like, and never get into a which version is best discussion because there are no winners in something opinion based. I also think heated discussions over something like that just make people look like idiots.

  42. Gabe says:

    With all these people talking about ways XP is better, I'm surprised nobody has complained yet with righteous indignation about the removal of the Marquee screensaver from newer versions of Windows.

  43. Troll says:

    "old Windows XP machine"?, XP is a supported OS. Please remove the word "old".

  44. Troll says:

    And "If you find". Windows 7 machines are harder to come across.

  45. Bill Gates says:

    255 characters ought to be enough for anybody.

  46. A.M. says:

    @Gabe: That might be implicated and constitute in someone's opinions the actual reason why XP is indeed better.

    On the serious side (only don't start throwing things at me, please), this transition – XP, Vista, Win7 – has somehow reminded me of the other one: 98, ME, 2000(deleted) XP. That should probably look as if I see Win7 as a proper replacement to XP, which I'm not prepared to deny.

  47. James says:

    Since for some weird reason this *has* descended into an XP vs Vista/7 mud-slinging match already, my 2 cents…

    I loved Win98SE and used it for years till I finally moved on to XP Pro SP2. I hated XP initially because among other things it didn't include real-mode DOS (for the record, WinME isn't worth mentioning as far as I am concerned). Eventually I set up a DOS/XP dual-boot and moved on… Similarly, I skipped Vista completely (gave it some thought after SP1, but XP suited me just fine). Last year, finally gave in and on my newer 64-bit machines installed Win7 Ultimate. I don't rate XP 64-bit highly enough to use it, maybe 'cos it was early days yet for x64 when it came out. XP SP3 still runs fine though on my older machines, and even on a newer Atom-based netbook that came with the ridiculous Win7 Starter that I got rid of immediately. Now as for Win7, I am a wee bit conflicted about it. It might seem less irritating to those used to Vista, but for a pro XP user, it comes across as being slightly dumbed down for the masses. For example, where is the useful "File Types" tab to allow me to change file type icons, edit the context menu etc., huh? Why was the status bar emasculated completely in Win7 Explorer, and why can't that stupid Details Pane show me the used/empty space on my HDD, nor indeed file size information for more than 15 files at a time (a completely arbitrary and ridiculous limit)? I could go on… These sort of things irritate me a lot, and it's not because I am stuck in my ways and am unwilling to change either. It's because try as I might, I just can't fathom the reasoning behind such design changes. Too many options confuse users, certainly, but too few and you run the risk of ending up with an OS that just looks pretty and is not worth much else. Admittedly, Win7 looks good and works well, but these small niggles are what make me yearn for XP sometimes. Oh well, I know one must move with the times, but I sincerely wish Win8 doesn't get dumbed down even further, for that will *really* break the camel's back and I'll switch to something else.

    [I already explained why the File Types dialog is gone: It never really worked right. -Raymond]
  48. James says:

    Hmm, thanks a lot for that link, Raymond! Actually, if I may clarify further, I have absolutely no problems whatsoever using RegEdit to make the necessary changes. However, whatever does one do when there is no longer any way to change the behavior any more? I have been Googling (err, Binging?) for a solution for more than a year now, and have not managed to find even an undocumented way to change that 15-file limit for the Details Pane. (*Completely* baffles me, that one does. Was the extremely useful XP status bar behavior changed due to Libraries in Win7? Due to issues with files over the network? Have you discussed this too anywhere?) If you know some super-secret way to change the limit to, say, 100 files or so, I literally beg you to let me know!

    BTW, if someone's inclined to respond with links to Classic Shell and so on, I know all the workarounds and 3rd party programs by now. I do not want to waste resources and possibly destabilize my system running 3rd party code that messes with/replaces the shell, and as for the Properties dialog, that existed in 9x/XP as well, and wasn't a substitute for the info. available at a glance in the status bar.

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