7 ms·

How to ensure that your program does not run under Windows 95 (1995) [pdf]

98 points by bcaa7f3a8bbc 6y ago

bcaa7f3a8bbc 6y ago
Summary of maxims: You can print out these two pages, fold than up, and keep then in your pocket. Well, maybe not, since nobody is really interested in writing MS-DOS-based games, anymore. But if you did, this would have been a handy guide to ensuring that your game doesn’t run on Windows 95. 1. The more confusing the error message, the better. 2. If it doesn’t run under Windows, then it’s Windows’fault. 3. Detect Windows, and crash. 4. Manuals are a waste of time. 5. Words in boldface don’t count. 6. Just because you’re a Windows application doesn’t mean that you have to be compatible with Windows. 7. Performance degradation is acceptable in the greater interest of not running on Windows 95. 8. If you’re going to do something wrong, do it wrong in as many different ways as possible. 9. Find a rule and break it as blatantly as possible. 10. The weirder your code, the harder it will be for the operating system to detect that you are about to do something stupid and rescue you. 11. Always look for the weirdest, most convoluted way of doing something. That way, you stand a good chance of doing it wrong. 12. It is better to be lucky than good. 13. Multitasking is for wimps. 14. Persistence may not help, but it’s fun. 15. Thrashing is good. It reminds the user that the computer is on. 16. Random addresses are harmless. 17. If you’re going to fail, do so as subtly as possible. 18. Do something that is supported only under Windows, and do it wrong. 19. Second-guess the specification whenever possible. 20. Knowledge of the English language is optional. 21. Well-behaved programs are for wimps. 22. Bite the hand that feeds you. 23. Words in italics don’t count. 24. If you can’t be subtle, then be blatant. 25. Intel will never release a new CPU. 26. Slower is better. 27. If you can’t convince the operating system to screw you up, take matters into your own hands. 28. Microsoft will never release a new version of the operating system. 29. The high words of 32-bit registers are always zero. 30. Even business applications can benefit from a boot disk. 31. Error checking is for wimps. 32. Don’t bother testing the error paths. The game is already over. 33. When faced with the unusual, self-destruct.
- redis_mlc 6y ago
  I was a Windows developer back in the day. After a certain Windows release, Microsoft had a Windows App Certification checklist of features you had to use if you wanted various levels of support, or sales to brick and mortar stores (they required that to reduce support calls and returns.) At first I found the checklists irritating, as they required essentially a major application release for each Windows version - your application bit-rotted essentially. But in the end, it was worth it as the application was more polished, with standardized paths, help, etc.
  - elwes5 6y ago
    The amount of crazy things people did in win3.x was pretty amazing. MS kind of did it to themselves. Want to know what an HWIN looks like? Right there in the header. No functions to access those items. Now you can not change that struct without breaking hundreds of programs. I remember the other devs grumbling that the win9x headers did not have the system structs in there. What was just an update into an a pointer deref became 'which method do I need to change this feature now...' game. That MS pulled that compat job off and did not absolutely obliterate everything I have to admire.
est31 6y ago
Had to smile when I read the epilogue: > Sometime after Windows 95 shipped and became a smash hit, a group of prominent game developers visited Microsoft as guests of the DirectX team. At some point, they learned of “this guy” on the Windows 95 team who worked so hard at getting all their games to work that he “officially went insane.” Thus intrigued, they asked to be introduced to this insane guy, and they presented me with a letter, signed by all of them, with the message, “Thanks for going insane.” > I still have that letter.
- RcouF1uZ4gsC 6y ago
  One of the big advantages Windows had on the desktop is the absolutely fanatical commitment to backwards compatibility. While this affected purity, it gave businesses the assurance that the software they owned would still continue to work.
  - Arainach 6y ago
    Has, not had. The vast majority of things still work flawlessly, and Microsoft continues to invest serious efforts in this area. I don't have any 32-bit programs on my computer which don't run on Windows 10, and I have plenty of older Win9x-era EXEs of various tools from developers which don't exist any more.
    - sterlind 6y ago
      Fun fact: You can still run 16-bit programs on 32-bit Windows 10!
      - swiley 6y ago
        How hard is it to install 32-bit windows 10 on a modern computer? I wouldn’t want to run that on an actual 32-bit only machine.
        kirb 6y ago
        It’ll work, may have to disable secure boot/enable legacy BIOS mode though. Of course you’ll be limited to 4GB RAM and there may be software you use that’s gone 64 bit-exclusive in the past few years.
gwbas1c 6y ago
I remember using custom boot disks for some games... Makes me wonder if Windows 95 should have just rebooted into DOS for older games. Alt-tab was always sketchy anyway when a have was running.
- koala_man 6y ago
  Almost all DOS games I played at the time worked fine in Windows 95. There were just a couple that I needed custom boot disks for.
- bawolff 6y ago
  Didnt it? I remember "reboot in msdos mode" being a thing.
  - ido 6y ago
    It could, but most DOS games worked fine inside win95.
fortran77 6y ago
This was a similar issue to trying to recompile OS9 programs under carbon to work on OSX.
fouc 6y ago
I briefly imagined this was going to be a treatise based on some reality where all windows programs could be trivially made to run on windows 95. Even 25 years later. It would be amusing to think that developers would have to take extra steps to ensure their program does not in fact run on older windows versions.
montjoy 6y ago
I remember terrible times trying to get some Lucasarts and Origin games going in that era. You want a cdrom -and- a sound card? That’s crazy talk. No no don’t use sound blaster’s driver use ours and our crazy ass memory manager too. Oops no sound for you! You’re in Windows! Etc etc. Thank goodness for autoexec.bat and config.sys.
- ehayes 6y ago
  Getting Wing Commander to work with a sound card, and a joystick, and in conventional memory was my intro to a lifetime working with computers.
  - montjoy 6y ago
    LOADHIGH my friend, LOADHIGH
raverbashing 6y ago
> Maxim 2: If it doesn’t run under Windows, then it’s Windows’ fault. And the preceding example is just hilarious. But hey "it works on my machine! it must be your fault!!11" It was similar shenanigans when a lot of Windows 95/98 "stopped working" when Windows 2000/XP worked. "What do you mean I can't write to C:/Windows whenever I want? What do you mean I can't put my config option in some hidden corner of the system registry?" sigh
- bcaa7f3a8bbc 6y ago
  > Maxim 6: Just because you’re a Windows application doesn’t mean that you have to be compatible with Windows. This one is more hilarious. pushf cli ... five instructions later ... popf ; BUG! Does not enable interrupts > What makes this noteworthy is not that it contains exactly the forbidden code sequence, it is noteworthy because this is not an MS-DOS application but rather a Windows application. It’s a Windows application doing something that doesn’t work under Windows. That takes nerves. A certain network driver does essentially the same thing. And, > Maxim 18: Do something that is supported only under Windows, and do it wrong. > Memory lock calls are ignored in the absence of virtual memory, so make sure to abuse lock functions as much as possible. That way, when you are run in a virtual memory environment, strange and wondrous things start happening that never happened in real mode. > Since none of the standard DOS extenders use virtual memory by default, this is an excellent opportunity to begin behaving randomly. This is so important it’s worth restating.
  - raverbashing 6y ago
    Yeah that cli missing the sti is baffling! What I find ironic is that while some people go on and on about gatekeeping programming and "you're not a real programmer if..." some people are just doing that kind of thing (and they're usually the ones making more money) I was satisified when I found out that Vista, amongst the many things it did wrong, did something right: started naming programs that were misbehaving (for example, taking too long to shutdown)
- kevingadd 6y ago
  One developer who frequented a forum I moderated started pitching a fit loudly upon the introduction of Windows XP because his software all relied on the ability to just fudge with other processes' memory at runtime in order to exchange information or do I/O (on files the other process had mapped). Windows XP breaking this profane behavior was, of course, an attack on his liberty and an attempt to break his software. Nevermind the fact that if you really want to touch another process's memory there IS a way to do it...
kccqzy 6y ago
I thought example 50 and 51 are pretty reasonable. Pointer tagging is a valid technique; it's a pity they chose to tag using the high bit instead of the low bit. But then 2GB of memory was humongous in the age of Windows 95. Also, didn't some 32-bit operating systems use to reserve the upper 2GB of the address space for the kernel?
- kevingadd 6y ago
  Windows carved out 2GB of address space for a very long time, there's a /3GB flag that you could set at boot time to reduce that carve-out to 1GB (freeing up another 1GB of address space for applications)
ComputerGuru 6y ago
By Raymond Chen, of course.
frabcus 6y ago
I felt the same in reverse trying to make a game (Creatures 3) work well on Windows 95/98 in late 1999. We did quite a few patches after release to fix odd compatibility bugs that came in via customer support. Some weren't directly Microsoft's fault. I remember there was a printer driver that would change the current directory of processes that it wasn't even being used in. I had to update the media code in the game to use absolute paths. It often felt like I was being paid by my company to work for Microsoft, which felt very clever of Microsoft at the time! Windows works because everyone, at Microsoft and outside, put in a lot of work to make it work.
- swiley 6y ago
  > Windows works because everyone, at Microsoft and outside, put in a lot of work to make it work. Maybe that’s a general property of platforms and operating systems, it would explain why people get so attached to them.
beigeoak 6y ago
Does anybody know the serif font that is used in the PDF? UPDATE: It seems to be "Adobe Jenson Pro Subhead" https://fonts.adobe.com/fonts/adobe-jenson https://fonts.adobe.com/fonts/adobe-jenson
Sevaris 6y ago
It seems this was one of two appendices to Raymond Chen's book "Old New Thing". The appendix doesn't exist in printed form for some reason though. It's a great book and definitely worth reading. The second appendix is titled "Tales of Application Compatibility" http://ptgmedia.pearsoncmg.com/images/9780321440303/samplechapter/Chen_bonus_ch01.pdf http://ptgmedia.pearsoncmg.com/images/9780321440303/samplech...
- branon 6y ago
  I saw "Old New Thing" and immediately wondered if this was Chen. Seen his blogs on HN before, didn't know there was a book!!
mfontani 6y ago
Wow, there's _pages_ and _pages_ of programs which would have been seemingly broken because they forget to "sti" after having "cli". It was one of those things we were taught to always, no matter what, do in high school -- one of those "do one thing, and always the inverse" - like push to stack, pop back from stack kind of thing. Really odd to see those things "out there"!
- bcaa7f3a8bbc 6y ago
  You missed its context. In real mode, the interrupt enable/disable status is controlled by the global CPU flag, in bit 9. If you saved the entire FLAGS register when interrupt was enabled with "pushf", and later you use "popf" to restore the flags, there's no reason to use "sti", since the interrupt bit was already restored, it was perfectly legal in real-mode DOS. However, in protected mode under an OS, it's unacceptable for a single program to disable interrupts of the entire CPU, so the global CPU interrupt flag is always enabled and controlled by the OS, but each program had its own virtual interrupt state controlled by "sti" and "cli", and cannot be changed by "pushf" and "popf" anymore. What actually happened: This problem was already recognized in the beginning, documentation contains multiple warnings and examples of correct code, but developers ignored all the warnings and instructions, continued misusing "popf" and doing it wrong in as many different ways as possible.
  - mfontani 6y ago
    It was a bit difficult to follow and the reasons behind why things failed weren't fully clear. I've also not written any asm in a couple decades... so, thank you very much for explaining this to me. It makes total sense now!

98 points by bcaa7f3a8bbc 6y ago

Summary of maxims: You can print out these two pages, fold than up, and keep then in your pocket. Well, maybe not, since nobody is really interested in writing MS-DOS-based games, anymore. But if you did, this would have been a handy guide to ensuring that your game doesn’t run on Windows 95. 1. The more confusing the error message, the better. 2. If it doesn’t run under Windows, then it’s Windows’fault. 3. Detect Windows, and crash. 4. Manuals are a waste of time. 5. Words in boldface don’t count. 6. Just because you’re a Windows application doesn’t mean that you have to be compatible with Windows. 7. Performance degradation is acceptable in the greater interest of not running on Windows 95. 8. If you’re going to do something wrong, do it wrong in as many different ways as possible. 9. Find a rule and break it as blatantly as possible. 10. The weirder your code, the harder it will be for the operating system to detect that you are about to do something stupid and rescue you. 11. Always look for the weirdest, most convoluted way of doing something. That way, you stand a good chance of doing it wrong. 12. It is better to be lucky than good. 13. Multitasking is for wimps. 14. Persistence may not help, but it’s fun. 15. Thrashing is good. It reminds the user that the computer is on. 16. Random addresses are harmless. 17. If you’re going to fail, do so as subtly as possible. 18. Do something that is supported only under Windows, and do it wrong. 19. Second-guess the specification whenever possible. 20. Knowledge of the English language is optional. 21. Well-behaved programs are for wimps. 22. Bite the hand that feeds you. 23. Words in italics don’t count. 24. If you can’t be subtle, then be blatant. 25. Intel will never release a new CPU. 26. Slower is better. 27. If you can’t convince the operating system to screw you up, take matters into your own hands. 28. Microsoft will never release a new version of the operating system. 29. The high words of 32-bit registers are always zero. 30. Even business applications can benefit from a boot disk. 31. Error checking is for wimps. 32. Don’t bother testing the error paths. The game is already over. 33. When faced with the unusual, self-destruct.

redis_mlc 6y ago
I was a Windows developer back in the day. After a certain Windows release, Microsoft had a Windows App Certification checklist of features you had to use if you wanted various levels of support, or sales to brick and mortar stores (they required that to reduce support calls and returns.) At first I found the checklists irritating, as they required essentially a major application release for each Windows version - your application bit-rotted essentially. But in the end, it was worth it as the application was more polished, with standardized paths, help, etc.
- elwes5 6y ago
  The amount of crazy things people did in win3.x was pretty amazing. MS kind of did it to themselves. Want to know what an HWIN looks like? Right there in the header. No functions to access those items. Now you can not change that struct without breaking hundreds of programs. I remember the other devs grumbling that the win9x headers did not have the system structs in there. What was just an update into an a pointer deref became 'which method do I need to change this feature now...' game. That MS pulled that compat job off and did not absolutely obliterate everything I have to admire.

est31 6y ago

Had to smile when I read the epilogue: > Sometime after Windows 95 shipped and became a smash hit, a group of prominent game developers visited Microsoft as guests of the DirectX team. At some point, they learned of “this guy” on the Windows 95 team who worked so hard at getting all their games to work that he “officially went insane.” Thus intrigued, they asked to be introduced to this insane guy, and they presented me with a letter, signed by all of them, with the message, “Thanks for going insane.” > I still have that letter.

RcouF1uZ4gsC 6y ago
One of the big advantages Windows had on the desktop is the absolutely fanatical commitment to backwards compatibility. While this affected purity, it gave businesses the assurance that the software they owned would still continue to work.
- Arainach 6y ago
  Has, not had. The vast majority of things still work flawlessly, and Microsoft continues to invest serious efforts in this area. I don't have any 32-bit programs on my computer which don't run on Windows 10, and I have plenty of older Win9x-era EXEs of various tools from developers which don't exist any more.
  - sterlind 6y ago
    Fun fact: You can still run 16-bit programs on 32-bit Windows 10!
    - swiley 6y ago
      How hard is it to install 32-bit windows 10 on a modern computer? I wouldn’t want to run that on an actual 32-bit only machine.
      - kirb 6y ago
        It’ll work, may have to disable secure boot/enable legacy BIOS mode though. Of course you’ll be limited to 4GB RAM and there may be software you use that’s gone 64 bit-exclusive in the past few years.

gwbas1c 6y ago

I remember using custom boot disks for some games... Makes me wonder if Windows 95 should have just rebooted into DOS for older games. Alt-tab was always sketchy anyway when a have was running.

koala_man 6y ago
Almost all DOS games I played at the time worked fine in Windows 95. There were just a couple that I needed custom boot disks for.
bawolff 6y ago
Didnt it? I remember "reboot in msdos mode" being a thing.
- ido 6y ago
  It could, but most DOS games worked fine inside win95.

fortran77 6y ago

This was a similar issue to trying to recompile OS9 programs under carbon to work on OSX.

fouc 6y ago

I briefly imagined this was going to be a treatise based on some reality where all windows programs could be trivially made to run on windows 95. Even 25 years later. It would be amusing to think that developers would have to take extra steps to ensure their program does not in fact run on older windows versions.

montjoy 6y ago

I remember terrible times trying to get some Lucasarts and Origin games going in that era. You want a cdrom -and- a sound card? That’s crazy talk. No no don’t use sound blaster’s driver use ours and our crazy ass memory manager too. Oops no sound for you! You’re in Windows! Etc etc. Thank goodness for autoexec.bat and config.sys.

ehayes 6y ago
Getting Wing Commander to work with a sound card, and a joystick, and in conventional memory was my intro to a lifetime working with computers.
- montjoy 6y ago
  LOADHIGH my friend, LOADHIGH

raverbashing 6y ago

> Maxim 2: If it doesn’t run under Windows, then it’s Windows’ fault. And the preceding example is just hilarious. But hey "it works on my machine! it must be your fault!!11" It was similar shenanigans when a lot of Windows 95/98 "stopped working" when Windows 2000/XP worked. "What do you mean I can't write to C:/Windows whenever I want? What do you mean I can't put my config option in some hidden corner of the system registry?" sigh

bcaa7f3a8bbc 6y ago
> Maxim 6: Just because you’re a Windows application doesn’t mean that you have to be compatible with Windows. This one is more hilarious. pushf cli ... five instructions later ... popf ; BUG! Does not enable interrupts > What makes this noteworthy is not that it contains exactly the forbidden code sequence, it is noteworthy because this is not an MS-DOS application but rather a Windows application. It’s a Windows application doing something that doesn’t work under Windows. That takes nerves. A certain network driver does essentially the same thing. And, > Maxim 18: Do something that is supported only under Windows, and do it wrong. > Memory lock calls are ignored in the absence of virtual memory, so make sure to abuse lock functions as much as possible. That way, when you are run in a virtual memory environment, strange and wondrous things start happening that never happened in real mode. > Since none of the standard DOS extenders use virtual memory by default, this is an excellent opportunity to begin behaving randomly. This is so important it’s worth restating.
- raverbashing 6y ago
  Yeah that cli missing the sti is baffling! What I find ironic is that while some people go on and on about gatekeeping programming and "you're not a real programmer if..." some people are just doing that kind of thing (and they're usually the ones making more money) I was satisified when I found out that Vista, amongst the many things it did wrong, did something right: started naming programs that were misbehaving (for example, taking too long to shutdown)
kevingadd 6y ago
One developer who frequented a forum I moderated started pitching a fit loudly upon the introduction of Windows XP because his software all relied on the ability to just fudge with other processes' memory at runtime in order to exchange information or do I/O (on files the other process had mapped). Windows XP breaking this profane behavior was, of course, an attack on his liberty and an attempt to break his software. Nevermind the fact that if you really want to touch another process's memory there IS a way to do it...

kccqzy 6y ago

I thought example 50 and 51 are pretty reasonable. Pointer tagging is a valid technique; it's a pity they chose to tag using the high bit instead of the low bit. But then 2GB of memory was humongous in the age of Windows 95. Also, didn't some 32-bit operating systems use to reserve the upper 2GB of the address space for the kernel?

kevingadd 6y ago
Windows carved out 2GB of address space for a very long time, there's a /3GB flag that you could set at boot time to reduce that carve-out to 1GB (freeing up another 1GB of address space for applications)

ComputerGuru 6y ago

By Raymond Chen, of course.

frabcus 6y ago

I felt the same in reverse trying to make a game (Creatures 3) work well on Windows 95/98 in late 1999. We did quite a few patches after release to fix odd compatibility bugs that came in via customer support. Some weren't directly Microsoft's fault. I remember there was a printer driver that would change the current directory of processes that it wasn't even being used in. I had to update the media code in the game to use absolute paths. It often felt like I was being paid by my company to work for Microsoft, which felt very clever of Microsoft at the time! Windows works because everyone, at Microsoft and outside, put in a lot of work to make it work.

swiley 6y ago
> Windows works because everyone, at Microsoft and outside, put in a lot of work to make it work. Maybe that’s a general property of platforms and operating systems, it would explain why people get so attached to them.

beigeoak 6y ago

Does anybody know the serif font that is used in the PDF? UPDATE: It seems to be "Adobe Jenson Pro Subhead" https://fonts.adobe.com/fonts/adobe-jenson https://fonts.adobe.com/fonts/adobe-jenson

Sevaris 6y ago

It seems this was one of two appendices to Raymond Chen's book "Old New Thing". The appendix doesn't exist in printed form for some reason though. It's a great book and definitely worth reading. The second appendix is titled "Tales of Application Compatibility" http://ptgmedia.pearsoncmg.com/images/9780321440303/samplechapter/Chen_bonus_ch01.pdf http://ptgmedia.pearsoncmg.com/images/9780321440303/samplech...

branon 6y ago
I saw "Old New Thing" and immediately wondered if this was Chen. Seen his blogs on HN before, didn't know there was a book!!

mfontani 6y ago

Wow, there's _pages_ and _pages_ of programs which would have been seemingly broken because they forget to "sti" after having "cli". It was one of those things we were taught to always, no matter what, do in high school -- one of those "do one thing, and always the inverse" - like push to stack, pop back from stack kind of thing. Really odd to see those things "out there"!

bcaa7f3a8bbc 6y ago
You missed its context. In real mode, the interrupt enable/disable status is controlled by the global CPU flag, in bit 9. If you saved the entire FLAGS register when interrupt was enabled with "pushf", and later you use "popf" to restore the flags, there's no reason to use "sti", since the interrupt bit was already restored, it was perfectly legal in real-mode DOS. However, in protected mode under an OS, it's unacceptable for a single program to disable interrupts of the entire CPU, so the global CPU interrupt flag is always enabled and controlled by the OS, but each program had its own virtual interrupt state controlled by "sti" and "cli", and cannot be changed by "pushf" and "popf" anymore. What actually happened: This problem was already recognized in the beginning, documentation contains multiple warnings and examples of correct code, but developers ignored all the warnings and instructions, continued misusing "popf" and doing it wrong in as many different ways as possible.
- mfontani 6y ago
  It was a bit difficult to follow and the reasons behind why things failed weren't fully clear. I've also not written any asm in a couple decades... so, thank you very much for explaining this to me. It makes total sense now!