Ti-83 模拟器与 ROM 的问题
我已经学习计算机和 C++ 知识有一段时间了，我决定尝试制作一个模拟器来获得更好的理解。我想尝试制作一个 TI-83 仿真器（在 Zilog Z80 CPU 上运行）。我目前有两个问题：
第一是指向当前指令的“PC”寄存器只有16位，但我下载的Ti-83 ROM是256Kb。 16 位数据如何指向超过 ~64Kb 的地址？
其次，ROM的入口点在哪里？执行是从0x0000开始吗？
谢谢，希望你能帮助我理解它是如何工作的。
I have been building knowledge of computers and C++ for quite a while now, and I've decided I want to try making an emulator to get an even better understanding. I want to try making a TI-83 Emulator (runs on a Zilog Z80 CPU). I currently have two problems:
The first is that the "PC" register that points to the current instruction is only 16 bits, but the Ti-83 ROM I downloaded is 256Kb. How is 16 bits of data supposed to point to an address beyond ~64Kb?
Secondly, where is the entry point on the ROM? Does the execution just begin at 0x0000?
Thanks, and hopefully you can help me understand a bit on how this works.
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处理器核心外部很可能有一个可编程分页寄存器，可以将其设置为一次将 256K 地址空间的一部分映射到 64K 地址空间的一部分。你需要模仿这一点。希望您可以在官方或非官方文档中了解这一点。如果您有原理图或 PCB，它甚至可能会显示为外部 PAL 或逻辑芯片集合。
我完全忘记了 z80 在重置时开始执行的位置，但我相信您会在处理器手册中找到它，这将是为其编写模拟器的必要工具。
您需要确保所使用的核心确实是 z80，而不是某种定制的扩展版本。
当然，我确信有人已经做到了这一点，所以你的项目可能更多地是关于学习的——尽管如果你工作足够长的时间，最终你可能会超越任何可用的解决方案。
There's is most likely a programmable paging register outboard of the processor core that can be set to map a portion of the 256K at a time into part of the 64K address space. You will need to emulate that. Hopefully you can find out about this in official or unofficial documentation. If you have a schematic or PCB it might even be visible as an external PAL or collection of logic chips.
I forget off the top of my head where a z80 starts executing on reset, but I'm sure you will find it in the processor manual, which would be a necessary tool to write an emulator for it.
You'll want to make sure the core used is truly a z80 and not some kind of custom extended version thereof.
And of course I'm sure someone has already done this, so your project is likely to be more about learning - though in the end you might surpass any available solution if you work on it long enough.
开发人员指南描述了内存的排列方式，尽管它没有它实际上描述了映射是如何工作的。
简短版本：地址空间分为四个 16K 页，其中第一个始终映射 32 页闪存 ROM 的页 0。
The Developer Guide describes how memory is arranged, although it doesn't actually describe how the mapping works.
Short version: the address space is divided into four 16K pages, the first of which always maps page 0 of the 32-page flash ROM.