Windows 9x CD-ROM device support fails with disks >= 256 MB

While trying to build a new Win95 image for v86 I noticed that the ATAPI CD-ROM support doesn't work.

As soon as the CD-ROM device is accessed I get blue-screens (recoverable) under Windows 95 like these:

Windows 95 example blue-screen screebshots

---

Windows 98 fails silently without blue-screens, but in both cases the D: folder is completely empty.

I tried using:

* the NEC CD-ROM driver from the Windows 95 boot floppy
* the OAK CD-ROM driver from the Windows 98 boot floppy
* the built-in CD-ROM driver of Windows 95 (which works under qemu, never tried it under v86)

Nothing helped, so I ran some more tests:

* happens both at the v86 main site and with a local build of current v86 HEAD
* happens both under SeaBIOS and Boch's BIOS
* happens both in v86 debug- and release-mode
* happens both using the Win95 and the Win98 image at the v86 main site (Win2K works)
* happens using my own Win95 image with OAK CD-ROM driver, from [here](https://github.com/copy/v86/pull/1325#issuecomment-2906349028) where I posted about having it working

I tried to fall back to the v86 repository state #1345 right when ATAPI CD-ROM support should be working:

```
git checkout d9088888e477663f0bf627a3e262d00af2849109
```

The problem was STILL there, that makes me doubt whether the released Win9x ATAPI support ever worked (what puzzles me is that I know that I had it working when I posted about it but now I can't reproduce it).

I can't remember if or when I last tested this after I had posted about it. Does it work for anybody else? Did it ever?

To summarize, CD-ROM support for Windows 9x appears currently broken, and it looks to me like it never worked.

**EDIT:** What does work is to boot from any boot floppy (Windows 95, Windows 98 or patcher9x) with a mounted CD-ROM image, I can access the CD just fine and run software from it.

Reproduce the failure with the Win95 and Win98 images, an ATAPI CD-ROM image, and the NEC or OAK driver; compare it with the working boot-floppy case and Win2K. Start at the ATAPI CD-ROM support and trace access from Windows 9x, using the reported SeaBIOS/Bochs and debug/release comparisons as checks. Done means Windows 9x can access the mounted CD-ROM and populate the D: drive without a blue-screen or silent failure.

Written by the indexing model from the issue text.