That's tough on today's owners.
While I know a lot about the vagarities of IRQs in these old systems, I didn't read if you are familiar with machines from those bad old days. Given the age of this system, I can't know if you remember those things we had to deal with back then.
But that's not your question. You ask the following:
1. Did the problem originate with the combo slot usage?
Possibly. Back then the combo slot shared the IRQ with the PCI and ISA slot. You may have to check the manual to discover this.
2. Was the problem simply a bad install of the PCI LAN card?
I'll write yes. The person handling the issue may not be from that era.
3. Why did both cards require an IRQ all to themselves?
That's how ISA worked. IRQ sharing didn't happen till later years.
4. Is this a 3Com thing?
5. I was able to turn off the use of the IRQ on the ISA card but not on the PCI card, why?
Most BIOS's didn't offer such for PCI IRQs, but again there is no standard here so I'll note a trick I used and that's to hog the IRQs by assigning them to the ISA bus and that way leave only specific IRQs for the PCI channels. Keep in mind that older PCI chipsets required one IRQ per slot. Given the age of the system, support costs usually cause this age machine to hit the dumpster wall.
6. Why was I unable to get the CDROM drive working with the ISA card installed (I was able to make it work in the past)?
Windows may or may not support said card or you needed it connected to some Sony card or sound card. Back then Sony made some drives with 40 pin connection that confuses today's tech gurus since they are not IDE but the connector fits. I find this an easy way to see how far back a tech's knowledge extends.
7. Anybody got any clues for me to chew on?
Most likely it's all configuration issues. Sadly I will not offer handholding on this one. It's best to go find another dumpster case which is newer and use that.
Bob (from pre CP/M days...)
7/9/02 Original configuration==> 200 MHz P55C Intel Pentium MMX CPU, 64Mb SIMM 72pin EDO RAM, Asus SP97-V motherboard,Win98se OS, 245watt AT power supply, Western Digital 2.5Gb hard drive, Sony CDROM drive, AT mini-tower case, 5.25 & 3.5 floppy drives, ISA Motorola Surf 56k PnP modem, SiS 5598 integrated VGA, 3Com EtherLink III ISA 3c509 LAN card, and a ISA SB16 sound card.
According to notes about the LAN card install, the CDROM drive was lost due to IRQ 15 being taken by the ISA LAN card. This was corrected by disconnecting the CDROM drive cable and then playing with the SiS hard drive controller?s default settings and then reconnecting the drive?s cable.
4 years later the computer was upgraded with additional 8Gb (partitioned into 4 logic drives) hard drive, S3 Stealth V64 video card replacing the onboard video setup, USB cabling, and 4 new sticks of RAM for a total of 256MB. During this upgrade the ISA LAN card was removed. According to notes about the upgrade, there were some problems getting the drives recognized by the OS. These problems were resolved and the system was found to be stable.
The computer was then put to use as a Linux lab. To facilitate connecting to the Internet while running Linux, a PCI LAN card was added. This caused a protection fault to occur. Win98se locked and wouldn?t come up in safe mode. Removing the card failed to free up the system, so a reinstall of Windows followed by the use of a backup file was the only way found to restore the system.
A review of install notes resulted in the following items of interest:
1) both the ISA card and the PCI card were located in the same slot of the motherboard (combo slot, PCI or ISA, please note not at the same time),
2) both cards were manufacture by 3Com,
3) both cards took complete use of an IRQ causing hardware conflicts,
4) based on past experience, the PCI card should have been an easy install, instead it caused a protection fault.
Based on the above items a repair/action list was created and follows below.
1) reinstall the ISA card in its original slot and see if it can be made to function.
2) do a system checkout to see if all devices are fully functional and if not attempt to make them work via driver reinstall or device reinstall.
3)disable the ISA card via OS?s Device Manager and install the PCI card in another open slot and see if it can be made to function.
4)remove the ISA card and see if the system will stabilize with the now reinstalled PCI card.
The outcome of the repair action list went as follows. The ISA card was functional but the CDROM failed. No actions brought back the CD drive. Disabled ISA card and installed PCI card which was functional. During the install the win98 CD was unusable so the following files were not available for the PCI card, rpcltc6.dll, nwlink.vxd, and wsipx.vxd (nwlink, rpcltc6.dll, and wsipx were found on the computer with collaborating dates of install). Removed the ISA card from the computer and booted. The PCI card caused the keyboard to fail but win98se came up and went into safe mode while the PC speaker beeped continuously. Restarted and some how win98 reassigned the system IRQs and the system became stable.
Present configuration==>200 MHz P55C Intel Pentium MMX CPU, 64Mb SIMM 72pin EDO RAM, Asus SP97-V motherboard,Win98se OS, 245watt AT power supply, 2 Western Digital 2.5Gb & 8Gb(partitioned into 4 logic drives) hard drives, Sony CDROM drive, AT mini-tower case, 5.25 & 3.5 floppy drives, PCI S3 Stealth V64 video card, LAN 3Com card 3C905-TX Fast EtherLink XL PCI 10/100 Base-TX Ethernet Adapter, ISA Motorola Surf 56k PnP modem, and a ISA SB16 sound card.
I?m left with questions as to what really happened. Did the problem originate with the combo slot usage? Was the problem simply a bad install of the PCI LAN card? Why did both cards require an IRQ all to themselves? Is this a 3Com thing? I was able to turn off the use of the IRQ on the ISA card but not on the PCI card, why? Why was I unable to get the CDROM drive working with the ISA card installed (I was able to make it work in the past)? Anybody got any clues for me to chew on?