Which cards do you have, pictures please.

My VLB I/O controller (PTI-255W) only has an IRQ setting for the parallel port. Can't do DMA as far as I know. On second thought, I think it can, but needs a driver to work?

Intel486dx33 wrote on 2025-01-09, 18:17:

I think I am getting IRQ conflicts causing the VLB to respond with “Controller error”

Links or pics for your motherboard, drive controllers, and storage devices would be handy. Check out theretroweb.com

You could try these things:
1) Remove any other IDE controllers, disable any on-board IDE controllers
2) Clean the contact pads on the controller edge connector, try a different slot , insert reinsert a couple times, same thing for the IDE pins.
3) Try a different storage device or drive cable
4) Triple check your jumpers and cable orientation and BIOS settings
5) Are you running at 40 or 50Mhz? Do you have more than 2 VLB cards in use?
6) Capacitors are weird. If the computer has not been used for a long longtime, maybe let the system sit for 5 minutes with the power on and then hit reset.

Okay,
I have a 486dx4@100mhz CPU
VLB motherboard

I tried other VLB slots with same results.
Funny, In bios setup the hard drive is detected and configured automatically.
But when I save settings and reboot I get a “Controller error”
And the drive is not detected.
Also I noticed the com ports are not detected.
Maybe some sort of IRQ conflict ?

Questions:
Should I use 33 or 50mhz bus speed ?
What IRQs should I use for com and parallel ports ?

Could you please post the make and model of your motherboard, drive controllers, and the storage devices that you are using? if you don’t know that, you can just post pictures.

Okay its a “DTC-2278D” VLB Controller card.
I have it all working but the Secondary IDE port/channel is not working correctly.
I am running Win-95b
In Device manager I see both IDE ports enabled and working fine.
The VLB controller is working fine.
All the Floppy drives work and the Primary hard drive works on the Primary IDE channel

On the Secondary port/channel
I tried different hard drives and CDROM drives.
I tried different cables.
But I cant get win-95 to see any devices on the Secondary Channel

I think maybe a jumper might be set wrong on the VLB card.
I am using a different VLB card right now and everything works okay.
So the problem is with the VLB card Secondary Channel and not my computer.

When booting from a Windows 98 boot disk, does it detect a CD-ROM drive on the secondary channel?
Which mainboard? No on-board I/O conflicting I presume?

Here are my computer Specs:

Motherboard - Vega vs486f VLB ( Young Micro Systems inc. ) ( $150 ).
http://www.elhvb.com/webhq/models/486vlb3/vs486f.html
CPU - Intel 486dx4-100 Overdrive ( $300 )
Cache - 256kb, -20ns
RAM - 32mb. ( 8 x 4mb, -60 ns , FPM ) ( $3200 )
Hard-drive - 240mb. ( IDE ) ( $240 )
Video - Cirrus logic 5429 ( 2mb , VLB ) ( $200 )
Audio - Sound Blaster Pro 2.0 ( ISA ) ( $300 )
Network - 3com 3c509 combo ( ISA ) ( $70 )
Controller - DTC-2278D, VLB ( 2 channels ) ( $60 )
CDROM - 2x Sony CDROM Drive with controller ( IDE ). ( $ 130 )
Floppy drives - 1.44mb. floppy and 5.25 1.2mb floppy drive. ( $100 )
Modem - US Robotics 2400 external modem. ( $150 )
SCSI - Adaptec AHA-1542CF ( ISA ) ( $100 )
Power supply - 300watt ( $60 )
Case - AT ( $75 )
OS - DOS 6.22 / Win3.11 ( $150 )

On the VLB controller cards Secondary channel I have the CDROM attached.
But it is not being recognized by the computer.
All the components in my computer work I have already confirmed this using another VLB card.
The problem is with the Secondary Channel on the VLB card.
It does not want to detect any drives.

Hmm did you read the text in the driver package at TRW ? https://theretroweb.com/expansioncards/s/data … ration-dtc2278d
I suggest you get it working in DOS first, then try Win95. There are no jumpers for the hd parts....That text has quite a bit of info as to secondary port, windows, etc...
You need the DOSEIDE.SYS driver loaded (as device=DOSEIDE.SYS /2 to enable second port), then load a cdrom driver.

3.1 DOS
----------

The DOS driver, DOSEIDE.SYS, needs to be loaded to support the
Secondary Port, turn on 32-bit mode, enable multi-sector transfers, and
program the DTC IDE card and each IDE device for optimal performance.

New C: drive installation:
* Insert MS-DOS boot disk in drive A: and reboot system.
* Partition the IDE drive with DOS FDISK and then perform DOS
FORMAT. Install DOS on the hard drive.
Existing C: drive has DOS installed and is bootable:
* Copy the DOSEIDE.SYS file to the root directory of the boot
drive.
* Add the following statement to the CONFIG.SYS file:

device=DOSEIDE.SYS

* To ENABLE the Secondary port on a Dual Port Card, modify the
CONFIG.SYS file by adding a "/2" to the driver lines as follows:

device=DOSEIDE.SYS /2

* Re-boot the system.

3.2 Windows 3.1x and Windows for Work Groups 3.11
----------------------------------------------------
All 32-bit DTC IDE controllers support 32-Bit Disk Access and 32-Bit
file access under Windows 3.11. The DTC Windows driver, WINEIDE.386, is
a Virtual Mode Driver (VxD) that can be used in place of WDCTRL.

* IT IS RECOMMENDED TO FIRST VERIFY THAT YOUR SYSTEM AND HARD DRIVE IS
* COMPATIBLE WITH THE 32-BIT DISK ACCESS FUNCTIONS UNDER WINDOWS USING
* THE BUILT IN WDCTRL DRIVER. IF YOU HAVE BEEN SUCCESSFUL USING THE
* WDCTRL DRIVER, THEN PROCEED WITH THE INSTALLATION OF THE DTC WINDOWS
* DRIVER - WINEIDE.386

The WINEIDE.386 driver provides the same functions, but also includes
32-bit PIO transfers to the DTC IDE card, supports multi-sector
transfers, and programs the DTC IDE card and each IDE device for optimal
performance.

* Copy the WINEIDE.386 file from the DTC Driver diskette into
the C:\WINDOWS\SYSTEM directory.
* Edit the file SYSTEM.INI located in the C:\WINDOWS directory.
Locate the [386Enh] section. If "32BitDiskAccess" is already
enabled (=on), you must disable the WDCTRL Driver by placing a
semi-colon (;) at the beginning of the line. Then add the
WINEIDE.386 driver line as follows:

32BitDiskAccess=on
device=*int13
;device=*wdctrl
device=wineide.386

If "32BitDiskAccess" is not enabled (=off), then add the
following lines to the beginning of the [386Enh] section:

32BitDiskAccess=on
device=*int13
device=wineide.386

3.3 Windows 95
----------------------------------------------------

The DTC Enhanced IDE product line is supported in Windows 95 with
WINEIDE.386. This Protected mode Enhanced IDE driver is a Virtual Mode
Driver (VxD) that offers features not found in the built-in driver.

* IT IS RECOMMENDED TO FIRST VERIFY THAT YOUR SYSTEM AND HARD DRIVE ARE
* COMPATIBLE WITH THE 32-BIT DISK ACCESS FUNCTIONS UNDER WINDOWS USING
* THE BUILT IN DRIVER. IF YOU HAVE BEEN SUCCESSFUL USING THE BUILT IN
* DRIVER, THEN PROCEED WITH THE INSTALLATION OF THE DTC ENHANCED IDE
WINDOWS DRIVER - WINEIDE.386

The WINEIDE.386 driver provides the same functions as the built in
driver, but also includes 32-bit PIO transfers to the DTC IDE card,
supports multi-sector transfers, and programs the DTC IDE card and each
IDE device for optimal performance.

* Copy the WINEIDE.386 file from the DTC Driver diskette into
the C:\WINDOWS\SYSTEM directory.
* Edit the file SYSTEM.INI located in the C:\WINDOWS directory.
Locate the [386Enh] section. You must disable the WDCTRL Driver if
you installed Windows 95 over Win 3.1x by placing a semi-colon (;) at
the beginning of the line. Then add the WINEIDE.386 driver line as
follows:

;device=*wdctrl ; Comment this line if exists
device=wineide.386 ; Add this line
__________________________________________________

This is Strange.
Its suppose to work out of the box with Win-95
Most other VLB cards work with both channels
Usually the driver is only required to enable 32-bit mode.
I am using a different VLB controller card right now and it works with both channels enabled by default without the need of a driver.

Things were different back then. VLB was a funny awkward time for PCs.

I suspect your new card has a Dip28 EPROM on it that contains an option rom that functions as the driver that is enabling your second ide port.

Okay, I see.
Once you install the EZIDE driver at boot it gives you the option to boot from Secondary Channel where your CDROM could be connected.
Pretty Cool for a 486 VLB card.
.