TONT 33023 关于无法再支持已经无人再制造的硬件这件事

原文链接：https://devblogs.microsoft.com/oldnewthing/20051209-12/?p=33023

Windows Vista will not have support for really old DVD drives. (The information below was kindly provided to me by the optical storage driver team.)

Windows Vista 对于一些特别老型号的 DVD 光驱已经不再提供支持了。（以下信息由光存储驱动开发组友情提供。）

When PC DVD drives first came out in 1998, the drives themselves did not have support for region codes but instead relied on (and in fact the DVD specification required) the operating system to enforce region coding, with the further understanding that starting on January 1, 2000 all newly-manufactured drives would support region coding in hardware rather than relying on software enforcement. For the purpose of this discussion, I will call the two types of drives “old” (manufactured before 2000) and “new” (manufactured on or after January 1, 2000).

1998年，PC 上的 DVD 光驱刚刚出现的时候，光驱硬件自身并不支持区码限制，而是依赖操作系统来确保这个限制（实际上也是 DVD 标准所要求的），不过在后来更新的标准中，自2000年1月1日起，所有新生产的DVD光驱都应当在硬件、而不是在软件中确保区码限制。为了讨论方便，接下来我将这两种光驱称作『旧』光驱（2000年以前生产）和『新』光驱（2000年1月1日起生产）。

It is that software enforcement that is going away. Turns out that the enforcement of region coding in software had its own problems:

在这个转变的过程中，由软件实现的区码限制消失了，原来是因为由软件实现的区码限制有它自己的问题：

• It was impossible for third-parties to compile their own CDROM.SYS from the source code in the DDK because the region code enforcement code was not included in the DDK.
  第三方开发者无法从DDK（驱动程序开发包）的源代码中编译他们自己的 CDROM.SYS，因为 DDK 中没有区码限制相关的代码。
• The region code enforcement code would sometimes mistake a new drive for an old one, resulting in customers unable to play DVDs. Even worse, the driver test team could not reproduce the problem reliably, and the problem went away entirely once a debugger was attached to the system.
  区码限制功能有时候会将新光驱当作旧光驱，导致客户无法播放DVD。更糟糕的是，驱动测试组无法可靠地复现这个问题，而且一接入调试器这个问题就消失了。
• The code to support the older drives is complex, and the drives that the optical storage team purchased prior to January 1, 2000 are dead or dying. Consequently, testing the code that provides support for old drives has become increasingly difficult, and when the last old drive finally gives up the ghost, testing will become impossible altogether.
  支持旧光驱区码限制的代码很复杂，并且在光存储团队在2000年1月日以前购置的（测试用）光驱大多已经或差不多坏掉了。由此，测试支持旧光驱代码的工作变得愈加困难，等到最后一台旧光驱坏掉的时候，测试工作就会变得完全无法进行了。

These were among the considerations which contributed to the decision to stop supporting these old drives.

以上这些都在决定停止支持这些旧光驱的考虑之中。

What does this mean for you? Almost certainly, the answer is “absolutely nothing”.

而这对你又意味着什么呢？基本可以肯定，答案是『毫无意义』。

First, there is no change to the way data is read from DVD drives, so data discs will still work the same way as they do today. Second, all new DVD drives will continue to run as they did before; the only change is that the risk of mis-identification as an old drive has been removed. Only if you have an old drive will you notice anything different, namely that encrypted/regionalized DVD movies will no longer play. And since the average drive lifetime is only three years, the number of such old drives that are still working is vanishingly small. Not even the optical drive test team can manage to keep their old drives alive that long.

首先，从DVD光驱中读取数据的流程没有任何改变，故而数据光盘的读取效果与现今别无二致。其次，所有的新DVD光驱都会像过去那样正常工作，唯一的变化是会造成将新光驱当作旧光驱这个失误的相关代码已经被移除了。只有当你手里的光驱是『旧』光驱的时候，你才会发现有不一样的情况发生，亦即加密的或有区码限制的DVD影碟无法播放。鉴于光驱的使用寿命平均只有三年，会有这个问题的旧光驱的数量正在急剧缩小。（别忘了，）就连光驱测试组的成员们都没法让这些旧光驱活那么久。