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Serial port PCI card on Windows 95

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First post, by Enderman

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Hello everyone, for work reasons (don't ask) I was tasked with assembling a Windows 95 PC. After several days I got it working (even with USB support), but the problem is that it needs two serial (RS-232, DB-9) ports, yet it only has one.

We bought a Digitus 2-port serial PCI card (https://www.digitus.info/en/products/computer … cards/ds-33003/), but I can't get it to work, because the oldest supported OS is Windows XP. I have tried other manufacturers' drivers with no luck.

This is no Virtual Machine, it is an actual W95 OSR 2.5 installed from CD-ROM and updated with the latest patches and USB support (plug and play and such).

If everything else fails I guess I could try to use a VM on a modern computer, but I'd like to avoid that if possible.

Do you know of any W95 PCI drivers for serial port cards?

Thanks in advance.

Reply 1 of 22, by Enderman

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I have also tried to use the GEMDOSIN.EXE utility (DOS program por managing ports). It finds a PCI card, but says that the 2 ports are "not programmed correctly" (I guess this is because the card is not properly installed).

Reply 3 of 22, by Enderman

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mekamayhem wrote on 2021-10-25, 12:08:

Could you use a splitter cable on the original port?

From what I see, that would mean both ends would get a copy of the same output, right? This is a PC that must be connected to two separate pieces of equipment, for industrial control stuff, so having one of the machines receive garbage or the wrong data is a no-no (they do different jobs and are not controlled the same way).

Google tells me there is also software to create virtual ports, but I don't think W95 would support that, may try.

Reply 4 of 22, by waterbeesje

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Maybe it would even be easier to find a motherboard that does support 2 serial ports oob? I know lots of them do, even up to the Pentium 4 era. If those boards still have 95 drivers, that could be your answer.

Stuck at 10MHz...

Reply 8 of 22, by leonardo

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Does your motherboard have ISA slots? eBay is littered with port cards for ISA, all of which would probably work with Windows 95 without additional drivers.
The bandwidth required for serial/parallel ports is low enough that it won't make a difference if the card is PCI or ISA.

[Install Win95 like you were born in 1985!] on systems like this or this.

Reply 9 of 22, by Enderman

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mekamayhem wrote on 2021-10-25, 12:49:

Thank you, sadly I've had no luck, those are Windows 98 drivers and the W95 wizard says it found none valid.

When I open Device Manager, it shows both an "Unknown device" and "PCI Card", it's probably the 2nd. I have also ran HWINFO.EXE but I doesn't find the card.

leonardo wrote on 2021-10-25, 12:53:

Does your motherboard have ISA slots? eBay is littered with port cards for ISA, all of which would probably work with Windows 95 without additional drivers.
The bandwidth required for serial/parallel ports is low enough that it won't make a difference if the card is PCI or ISA.

I'm afraid not, the computer is old, but not that old. Maybe I'll have to buy an older computer with 2 serial ports...

I guess I could also try to get the software running in W98, I've heard they are 99% compatible, is that right? I should test it thoroughly before, wouldn't want a nuclear meltdown or anything 😀

Reply 10 of 22, by leonardo

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Enderman wrote on 2021-10-26, 06:44:
leonardo wrote on 2021-10-25, 12:53:

Does your motherboard have ISA slots? eBay is littered with port cards for ISA, all of which would probably work with Windows 95 without additional drivers.
The bandwidth required for serial/parallel ports is low enough that it won't make a difference if the card is PCI or ISA.

I'm afraid not, the computer is old, but not that old. Maybe I'll have to buy an older computer with 2 serial ports...

I guess I could also try to get the software running in W98, I've heard they are 99% compatible, is that right? I should test it thoroughly before, wouldn't want a nuclear meltdown or anything 😀

Windows 95 is that old. 😁 Even most PIII-systems still have ISA-slots... ...and on that note also twin-serial ports. What kind of a system are you building - how did you manage to find a motherboard without ISA or serial-ports?
Even for PCI cards, it would seem you probably struck really bad luck to find one that doesn't support everything up from DOS and OS/2...

[Install Win95 like you were born in 1985!] on systems like this or this.

Reply 11 of 22, by Enderman

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It's an early Windows XP computer actually. It took me several days to get Windows 95 installed and running, I had to patch it to hell and back... Never done anything like this before, last time I used that OS my age was a single digit!

It actually worked alright once patched (fast CPU patch, high mem patch, USB patch...), except for the GPU driver and, of course, this PCI serial port card.

The previous system malfunctioned (it's totally fried) and this was the oldest PC we had to replace it. The old one did have two serial ports, plus ISA slots of course. Pity.

I'm currently trying my luck getting Windows 98 installed and working (video card drivers at least work now, no longer 640x480, phew), and if the PCI card still doesn't appear, I think I'll go for the virtualization route.

This is work stuff, of course, wish I was doing it so I can play Tomb Raider...

Reply 12 of 22, by leonardo

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Enderman wrote on 2021-10-26, 10:53:
It's an early Windows XP computer actually. It took me several days to get Windows 95 installed and running, I had to patch it t […]
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It's an early Windows XP computer actually. It took me several days to get Windows 95 installed and running, I had to patch it to hell and back... Never done anything like this before, last time I used that OS my age was a single digit!

It actually worked alright once patched (fast CPU patch, high mem patch, USB patch...), except for the GPU driver and, of course, this PCI serial port card.

The previous system malfunctioned (it's totally fried) and this was the oldest PC we had to replace it. The old one did have two serial ports, plus ISA slots of course. Pity.

I'm currently trying my luck getting Windows 98 installed and working (video card drivers at least work now, no longer 640x480, phew), and if the PCI card still doesn't appear, I think I'll go for the virtualization route.

This is work stuff, of course, wish I was doing it so I can play Tomb Raider...

You could usually run Windows 95 on systems that shipped with 98... maybe even ME - but by the time XP was the default, likely the hardware was such that you wouldn't find drivers for it any more, and also the legacy stuff like parallel ports, serial ports and ISA-slots were already out.

That said Windows 95 does cover an impressive range of hardware, if you consider you can basically run it on a 386 (486 really) to an early Pentium 4 or Athlon-based system (P3, if you're realistic). It looks like your system is just new enough to not really be viable.

[Install Win95 like you were born in 1985!] on systems like this or this.

Reply 13 of 22, by llm

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Enderman wrote on 2021-10-25, 10:57:

This is no Virtual Machine, it is an actual W95 OSR 2.5 installed from CD-ROM and updated with the latest patches and USB support (plug and play and such).

i can't help but out of curiosity:

what software does run on Win95 but not on Win98/XP? i had a very crippled game one time that would only run on Win98 but only on Win95?

Reply 14 of 22, by Enderman

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I finally managed to get the card working on W98. Also, the video card and network adapter, and USB flash drives too. It was a bit of a struggle though hehehe. Wouldn't want to do it again.

Indeed I used the MCS9865 drivers you linked. I removed the card (with the computer off that is), rebooted, plugged it back in, and W98 told me on boot that it had found new hardware, a "Serial PCI port" or something. I pointed it to the drivers (strangely, I had to copy them to a floppy disk, as the dialog would not let me choose a folder inside My Documents as the source, the button was greyed out). They installed OK and two new ports appeared, COM5 and COM6.

I downloaded and ran the SerialTest Diagnostic Utility (https://connecttech.com/resource-center/portm … nostic-utility/) and all 3 ports worked allright with a loopback cable. Now I have to check if the old software runs on W98, which I think it'll do because it's compatible with 95.

Just for your information, I checked and the computer is a Dell Optiplex 170L, way more modern than I thought. Anything older had been recycled already.

llm wrote on 2021-10-26, 14:09:

i can't help but out of curiosity:

what software does run on Win95 but not on Win98/XP? i had a very crippled game one time that would only run on Win98 but only on Win95?

The problem here is that this SCADA software is used for some critical stuff (yes, believe me, and this is more usual than you'd think, I'm sure NASA is still using Windows 3.1 somewhere) and we can't risk running it on XP in case something fails. In fact I'm gonna test it exhaustively in 98 before calling it a day, but I've heard 95 and 98 are basically the same except for the driver system and a couple of things.

Reply 15 of 22, by llm

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Enderman wrote on 2021-10-27, 07:55:

The problem here is that this SCADA software is used for some critical stuff (yes, believe me, and this is more usual than you'd think, I'm sure NASA is still using Windows 3.1 somewhere) and we can't risk running it on XP in case something fails. In fact I'm gonna test it exhaustively in 98 before calling it a day, but I've heard 95 and 98 are basically the same except for the driver system and a couple of things.

i wouldn't be surprised if NASA uses way older stuff (and the industrial sector)

and Win95 and Win98 are not that different - i would also say that WinXP was a bigger step

don't forget to give an update when everything is working!

Reply 18 of 22, by Enderman

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Success! That old software runs OK on W98. I doubt it'll run on XP though, I will try one of these days. Will keep a backup just in case.

Still got to test this PC on site with the actual hardware, but I'm 90% done now.

Zerthimon wrote on 2021-10-27, 10:01:

What about a USB serial port adapter ? Would that work for you ?

I'm not sure either 95 or 98 would support that, perhaps the latter. But luckily I won't have to find out...

Last edited by Enderman on 2021-10-31, 16:02. Edited 1 time in total.