模拟器是如何工作的?当我看到NES/SNES或C64模拟器时,我很震惊。

您是否必须通过解释特定的组装指令来模拟这些机器的处理器?还有什么?它们通常是如何设计的?

你能给那些对编写模拟器(特别是游戏系统)感兴趣的人一些建议吗?


当前回答

关于模拟真实系统或你自己的东西的建议? 我可以说模拟器通过模拟整个硬件来工作。也许不是电路(像HW那样四处移动比特)。移动字节是最终结果,所以复制字节是好的)。模拟器是很难创建的,因为有很多黑客(如在不寻常的效果),时间问题,等等,你需要模拟。如果一个(输入)部分是错误的,那么整个系统就会崩溃,或者最多出现一个bug/小故障。

其他回答

当你开发一个模拟器时,你是在解释系统正在运行的处理器组件(Z80、8080、PS CPU等)。

您还需要模拟系统拥有的所有外设(视频输出、控制器)。

你应该开始为简单的系统编写模拟器,比如旧的Game Boy(使用Z80处理器,我是不是没有弄错)或C64。

一个叫维克多·莫亚·德尔·巴里奥的人写了一篇关于这个主题的论文。152页里有很多有用的信息。你可以在这里下载PDF文件。

如果您不想注册scribd,您可以谷歌获取PDF标题,“模拟编程技术的研究”。PDF文档有几个不同的来源。

在创建了我自己的80年代BBC微型计算机模拟器(类型VBeeb到谷歌)后,有许多事情要知道。

You're not emulating the real thing as such, that would be a replica. Instead, you're emulating State. A good example is a calculator, the real thing has buttons, screen, case etc. But to emulate a calculator you only need to emulate whether buttons are up or down, which segments of LCD are on, etc. Basically, a set of numbers representing all the possible combinations of things that can change in a calculator. You only need the interface of the emulator to appear and behave like the real thing. The more convincing this is the closer the emulation is. What goes on behind the scenes can be anything you like. But, for ease of writing an emulator, there is a mental mapping that happens between the real system, i.e. chips, displays, keyboards, circuit boards, and the abstract computer code. To emulate a computer system, it's easiest to break it up into smaller chunks and emulate those chunks individually. Then string the whole lot together for the finished product. Much like a set of black boxes with inputs and outputs, which lends itself beautifully to object oriented programming. You can further subdivide these chunks to make life easier.

Practically speaking, you're generally looking to write for speed and fidelity of emulation. This is because software on the target system will (may) run more slowly than the original hardware on the source system. That may constrain the choice of programming language, compilers, target system etc. Further to that you have to circumscribe what you're prepared to emulate, for example its not necessary to emulate the voltage state of transistors in a microprocessor, but its probably necessary to emulate the state of the register set of the microprocessor. Generally speaking the smaller the level of detail of emulation, the more fidelity you'll get to the original system. Finally, information for older systems may be incomplete or non-existent. So getting hold of original equipment is essential, or at least prising apart another good emulator that someone else has written!

共享源设备模拟器包含PocketPC/智能手机模拟器的可构建源代码(需要Visual Studio,在Windows上运行)。我参与了二进制版本的V1和V2。

它解决了许多仿真问题: -从虚拟客户端到物理客户端再到虚拟主机的高效地址转换 - JIT编译客户代码 -模拟周边设备,如网络适配器、触摸屏和音频 - UI集成,主机键盘和鼠标 -保存/恢复状态,用于模拟从低功耗模式恢复

模拟可能看起来令人生畏,但实际上比模拟容易得多。

任何处理器通常都有一个编写良好的描述状态、交互等的规范。

如果您根本不关心性能,那么您可以使用非常优雅的面向对象程序轻松地模拟大多数老式处理器。例如,X86处理器需要一些东西来维护寄存器的状态(简单),需要一些东西来维护内存的状态(简单),还需要一些东西来接收每个传入的命令并将其应用到机器的当前状态。如果您真的需要准确性,您还可以模拟内存转换、缓存等,但这是可行的。

In fact, many microchip and CPU manufacturers test programs against an emulator of the chip and then against the chip itself, which helps them find out if there are issues in the specifications of the chip, or in the actual implementation of the chip in hardware. For example, it is possible to write a chip specification that would result in deadlocks, and when a deadline occurs in the hardware it's important to see if it could be reproduced in the specification since that indicates a greater problem than something in the chip implementation.

当然,电子游戏的模拟器通常关心性能,所以它们不会使用简单的实现,它们还包括与主机系统的操作系统接口的代码,例如使用绘图和声音。

考虑到老式电子游戏(NES/SNES等)非常缓慢的性能,在现代系统上进行仿真相当容易。事实上,更令人惊讶的是,你可以下载一套SNES游戏或Atari 2600游戏,考虑到当这些系统流行时,免费访问每个卡带都是一个梦想。