Hi, I'm not sure if I fully understand.
Windows for Workgroups 3.11 has two HDD options.

32-Bit Disk Access (32BDA, aka FastDisk), which simply is an HDD driver that runs in Protected-Mode.
It's 32-Bit in the sense that it uses an VXD device driver (*.386 on Windows 3.x).
The original WD driver shipped with Windows 3.1x is very limited and assumes MFM/RLL era drives.
It predates IDE/EIDE, uses the plain WD1003 command set of the mid-80s.
Then there are third-party drivers such as the MicroHouse driver, which are more modern.

32-Bit File Access (32BDFA), which simply is an HDD cache (not CD/floopy cache) that runs in Protected-Mode.
It's 32-Bit in the sense that it uses an VXD device driver (*.386 on Windows 3.x).

More information:
https://en.wikipedia.org/wiki/Microsoft_32-bit_file_access
https://en.wikipedia.org/wiki/Microsoft_32-bit_disk_access

https://stason.org/TULARC/pc/enhanced-IDE-faq … ccess_work.html

https://www.os2museum.com/wp/how-to-please-wdctrl/

Ideally, both are enabled for best performance. And swapfile is set to permanent (a big, hidden and fixed file that doesn't move).
Because then, Windows for Workgroups nolonger uses DOS to call the disk, both in13h and int21h calls are filtered by Windows now.
Windows now stays in Protected-Mode all the time (doesn't need Real-Mode DOS or V86 DOS).
It now can use DOS VMs in a better way, too: Programs can better run in a window, mouse integration etc.
(-> Using MS Mouse 9 driver can help here, too).

How to disable/enable manually:
In SYSTEM.INI, set 32BitDiskAccess=ON or 32BitDiskAccess=OFF
In SYSTEM.INI, set 32BitFileAccess=ON or 32BitFileAccess=OFF

However, running SmartDrive with double buffering might give better overall performance.
It can cache CD and floppy access, too, for example.
On modern hardware past Pentium, the BIOS/UDMA drivers might have better performing code than the Windows HDD driver.
Tip: Helix Multimedia Cloaking has a SmartDrive alternative that takes up little RAM below 1 MB.

About secondary IDE/ATAPI ports.. They don't need BIOS support.
Not for CD-ROM access, at least. If they're active on the standard ports the CD-ROM drivers will detect and use them without help of the BIOS.
So any IDE ISA card with jumpers for IDE will work out of box.
The others, the PnP soundcards with IDE, for example, need an init utility for DOS, to enable the IDE port.
It's just booting that doesn't work without BIOS support.

Jo22 wrote on 2026-09-20, 02:08:

Hi, I'm not sure if I fully understand.
Windows for Workgroups 3.11 has two HDD options.

Thanks for your prompt answer, and super detailed explanation. It matches what I got from the various internet sources on the topic. I'll provide some additional details for a better context.

The disk I use is an HP 1GB [0] with the Micro house 32 bit driver. Then, in wfw 3.11 I've enabled both 32bit access to drive, and 32 bit access to files (caching).
Originally, the HDD was master, and the CD Drive slave on the same channel (primary). So they share the same cable.
With the above setup the game is totally disrupted in performances when launched from wfw3.11, while it works ok when started in pure dos.
I've got a little better performance by disabling the 32 bit caching, for whatever the reason.

So my theory was: the same cable being used for HDD + CD is disrupting performances while using the Microhouse driver. Hence wanted to move to 2 IDE cables with primary + secondary channels to isolate the low performing CD drive. Trying to achieve this, assuming the theory is correct, I've found no solutions to be applicable with the two I/O cards I own. Both have only 1 IDE connector. VLB has a primary/secondary switch which appereantly is not BIOS recognized - maybe this is an emulation handled by the IC to overcome the BIOS 2 drives limitations? - While the ISA card has 2 jumpers which are IDE/AT enable, and primary enable/secondary disabled (as per the retro web manual). No combination would work (also tested CD ROM drive master/slave combinations in any configuration as per above). By tweaking jumpers I end up with the BIOS not being able to recognize the disk, or BIOS autedect to endlessly trying, which hints me of bus conflict. Any other combinations where the HDD was to be seen would end up with MSCDEX not being able to pick up the CD drive.

In the end now I'm not sure what's the issue, and how to overcome.

P.s. What you're saying about CD drives not passing through BIOS int 13h is interesting, would explain why CD allocation in the BIOS was set to None back in the days. It was all about the real mode MSCDEX driver to pick it up. Never thought of that.

[0] https://theretroweb.com/harddrives/4767

Jo22 is saying you can have the CD-ROM on the second IDE cable, even though BIOS doesn't recognise it.

The CD-ROM will be loaded in DOS via these lines:
autoexec.bat: "MSCDEX.EXE /D:CD01"
config.sys: "DEVICE=CD1.SYS /D:CD01"

CD1.sys is the driver. MS DOS 6.22 may other drivers such as CD1.SYS, CD2.SYS, CD3.SYS, CD4.SYS , or named drivers. More info: https://dfarq.homeip.net/using-a-cd-rom-drive-in-ms-dos/

You'll have a working CD-ROM in DOS. Most likely compatible with Win 3.11 and earlier, but not Win95 and later.

DOS programs under Windows have overheads.
Also, there is a Goldstar 32BDA driver and a DOS VLB drivers for the card https://theretroweb.com/expansioncards/s/goldstar-miovlu6-aa - using them together might improve things

Matth79 wrote on 2026-09-20, 20:17:

DOS programs under Windows have overheads.
Also, there is a Goldstar 32BDA driver and a DOS VLB drivers for the card https://theretroweb.com/expansioncards/s/goldstar-miovlu6-aa - using them together might improve things

I've tested the driver already, it only works for HDD up to xxx MB (768 iirc?). That's why I opted for the Micro House driver. Note I've also contributed to that page by sending pictures of my card, see the name 😀

Btw, I trust your considerations, still it's not working. I figured I wasn't clear on what I'm trying to achieve: I would want to have HDD on Primary IDE and the CD drive on Secondary IDE. Primary coming from the VLB card, Secondary coming from the Goldstar 16 bit ISA card. Two separate cables. This is my idea to overcome to the bottleneck in Wfw 3.11.

I've tested the solution without any touch up of my config.sys/autoexec.bat - which work OK with HDD master + CD slave on a single cable, and I'm attaching the results. Nothing works out.

I'm fairly sure this is due to the Goldstar ICs not having a proper way to configure primary/secondary when being used one another.

My read, and I'll use the back view of the ISA for ref, to set as Secondary and nothing else.
J1 2-3 FDD dis
-
J3 1-2 IDE en
J4 2-3 IDE sec
J5 2-3 ser1 dis
-
J7 2-3 ser2 dis
-
J9 2-3 LPT dis
-
J11 2-3 GAME dis
J12 to J15, don't care, maybe leave open

https://dosdays.co.uk/topics/Software/optical_downloads.php
May need to use DEVICE=VIDE-CDD.SYS /D:MSCD001 /P:170,15 to ensure it's looking for a drive on secondary, also set CD drive to master

UH-OH!
The MIOVLU6-AA VLB has a VLB IDE chipset and a Prime 2C, if they messed up and put the Prime 2C IDE as secondary instead of disabled, then it will never work with another card as secondary, and then with that set as secondary, that might merely flip the other one to primary.
One other thought, a good many of those settings should have caused conflict, does the ISA card actually work on it's own

Matth79 wrote on 2026-09-21, 22:10:

My read, and I'll use the back view of the ISA for ref, to set as Secondary and nothing else. J1 2-3 FDD dis - J3 1-2 IDE en J4 […]
Show full quote

My read, and I'll use the back view of the ISA for ref, to set as Secondary and nothing else.
J1 2-3 FDD dis
-
J3 1-2 IDE en
J4 2-3 IDE sec
J5 2-3 ser1 dis
-
J7 2-3 ser2 dis
-
J9 2-3 LPT dis
-
J11 2-3 GAME dis
J12 to J15, don't care, maybe leave open

Yup, forgot to add the [0] is ok for jumper reference.

UH-OH!
The MIOVLU6-AA VLB has a VLB IDE chipset and a Prime 2C, if they messed up and put the Prime 2C IDE as secondary instead of disabled, then it will never work with another card as secondary, and then with that set as secondary, that might merely flip the other one to primary.

Same thinking...that is why I'm now buying a UMC based card with primary+secondary connectors, to end up with just 1 VLB I/O card...stay tuned.

One other thought, a good many of those settings should have caused conflict, does the ISA card actually work on it's own

I agree it has conflicts, just wanted to rule out any anything. And yes, the ISA card has been forever working alone with this PC. The VLB was an upgrade I did 2 years ago, the PC is with me since...1998 something?

[0] https://theretroweb.com/expansioncards/s/gold … -prime-2c-mkiii