Windows NT 4.00 / NT 3.51 video subsystem issues

[bearwindows]

All revisions (ALPHA/I386/MIPS/PPC) of Windows NT 4.0 and Windows NT 3.51 has issue with maximum possible total video mode count limit and it is around 296 modes. Any mode provided by driver above 296 will be cutted down. It is not depended on driver issue, this bug is inside Windows NT system itself. Windows 2000 and later does not have such issue.

Here it is a binary patch for Windows NT 4.0 (I386, any SP/edition, language) for SYSTEM32\WIN32K.SYS :

1. Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0x6A to 0x68 0xB8 0x00 0xFF 0x03 0x00 0x6A
2. Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xFF to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xFF
3. Recalculate checksum, f.e. EDITBIN.EXE WIN32K.SYS /RELEASE

Here it is a binary patch for Windows NT 3.51 (I386, any SP/edition, language) for SYSTEM32\WINSRV.DLL :

1. Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xA1 to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xA1
2. Change 0x68 0xB8 0x00 0xFF 0x00 0x00 0xFF to 0x68 0xB8 0x00 0xFF 0x03 0x00 0xFF
3. Recalculate checksum, f.e. EDITBIN.EXE WINSRV.DLL /RELEASE

This will increase total limit to 1190 modes. Below are results in screenshots, before and after.

Edited Tuesday at 08:14 PM by bearwindows

[Start Me Up]

Thank you for sharing the patch @bearwindows

I haven't seen you around for, um, at least a few years now. Anyway, I'm glad that you are still active.

You have worked a lot on Windows NT 4 in the past. But did you also stumble over bugs in win32k.sys of Windows 2000 while you were working on your universal VBE driver? I would be interessed if you have any patches for win32k.sys of Windows 2000.

But you are right that the bug with the limitation of display modes doesn't seem to exist in Windows 2000. My graphics driver announces about 11,000 display modes and Windows 2000 seems to be able to handle it. Desk.cpl is a bit slow with many modes but there doesn't seem to be a real bug in Windows 2000.

Edited 1 hour ago by Start Me Up