[Solved] Moved to WIN10 host now can't get LPT working with DOS Guest

[trippingslowly]

Had LPT working under win7.

Went to Windows 10 and upgraded Virtualbox to 5.1.4r but now I can't get the LPT port to work.

Ran the following on the DOS VM

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    VBoxManage modifyvm "My VM Name" --lptmode1 "LPT1:"
    VBoxManage modifyvm "My VM Name" --lpt1 0x378 7

Now when I run VBOX and start the DOS VM I get the error:



Since I upgraded Vbox and Windows, should I make a new DOS VM or should the old one be ok?

Any idea what the error is saying?

[mpack]

It's possibly saying that the code VirtualBox uses to hook into the host LPT driver doesn't work on Windows 10. It wouldn't surprise me - the only surprise would be if it worked on Win64 hosts at all.

Unfortunately I am now two hardware generations removed from the last PC of mine which included an LPT port, so there's no way for me to reproduce this.

What is the DOS device doing that requires LPT?

[trippingslowly]

I have a vintage Xilinx design program which needs a dongle on the LPT port.

Is there anything I can do to get this working? Some days I wish I stayed on Windows 7 lol.

[michaln]

Does Windows 10 even support parallel ports?

[mpack]

I'd guess yes, since why throw away code that already exists? Unfortunately, as mentioned, I don't have any PC with an LPT to test it.

[trippingslowly]

Does Windows 10 even support parallel ports?

The LPT card (PCI) had a win10 driver 32 and 64-bit. And it shows up in device manager as working.

Somehow Virtualbox can't access it. It worked in Win7. I installed the 64 bit driver...should I try the 32bit one?

I tried to go back to vbox v5.0.18 but it won't even start on Win10. So have to use 5.1.4.

Ugh this throws a monkey wrench into things.

[mpack]

Somehow Virtualbox can't access it. It worked in Win7. I installed the 64 bit driver...should I try the 32bit one?

Non sequiter. You don't have a choice, unless you want to change hosts. Otherwise, if you have a 64bit host you install the 64bit driver. If you have a 32bit host it will require the 32bit driver.

[trippingslowly]

Could it be dependent on a certain PCI card? My motherboard doesn't have LPT so I added the card. I'm willing to buy a different one if I knew it would work.

*Edit* Tried a different LPT card and same thing. Seems something between Win10 anniversary update and Vbox 5.1.4 has totally borked.

Has anyone gotten host LPT to work through DOS VM on Win10?

And BTW, why isn't Parallel Port support built in to VBOX? It's very important in DOS with regards to dongles and printers.

[mpack]

Could it be dependent on a certain PCI card?

Naturally. Yes, you need a driver for that certain card. If you have a 64bit host that driver will need to be 64bit. And so on. These two statements are not in conflict.

If you have an LPT card installed in a Windows 10 PC then please answer Michal's question: does LPT work for anything at all in the host? - leave VirtualBox out of the discussion for the moment. Set your dongle aside too. You need to prove that the elements work before you can put them together.

[michaln]

And BTW, why isn't Parallel Port support built in to VBOX? It's very important in DOS with regards to dongles and printers.

You just answered your question.

DOS is not very important, it does not even rate as "important". DOS + parallel-port dongle is the very definition of unimportant in 2016. Just finding a PC with any kind of parallel port support is getting really hard (try that with a laptop, which is what almost everyone uses nowadays).

All the parts related to parallel port support in VirtualBox are open source and we welcome contributions. The support could certainly be improved, but it's simply not something important to Oracle customers.

[trippingslowly]

And BTW, why isn't Parallel Port support built in to VBOX? It's very important in DOS with regards to dongles and printers.

You just answered your question.

DOS is not very important, it does not even rate as "important". DOS + parallel-port dongle is the very definition of unimportant in 2016. Just finding a PC with any kind of parallel port support is getting really hard (try that with a laptop, which is what almost everyone uses nowadays).

All the parts related to parallel port support in VirtualBox are open source and we welcome contributions. The support could certainly be improved, but it's simply not something important to Oracle customers.

I see your point. I'm glad the code is in there though and hope it can be improved to work with the current build of Windows10. If not, I can always boot back into win7 to use the vm.

I didn't realize it before, but I actually think it was working in windows 10 until the recent "anniversary update " which caused all kinds of problems.

[trippingslowly]

Ok, got it working....here's how it worked for me.

I uninstalled the driver in device manager and rebooted windows 10.

When the machine was up again, the device had magically come back under device manager as LPT2.

So I looked in my .vbox file for the VM I am using and saw this:

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      <LPT>
        <Port slot="0" enabled="true" IOBase="0x378" IRQ="7" path="LPT1:"/>
        <Port slot="1" enabled="false" IOBase="0x378" IRQ="7"/>
      </LPT>
 

So it was looking for LPT1 in slot 0. On a hunch I changed it to this:

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      <LPT>
        <Port slot="0" enabled="false" IOBase="0x378" IRQ="7"/>
        <Port slot="1" enabled="true" IOBase="0x378" IRQ="7" path="LPT2:"/>
      </LPT>
 

I then changed the device manager settings to this:



And lo and behold it works now!

Hope this can help someone else.

[mpack]

Thanks, so your LPTx number on this host somehow got changed, but otherwise everything works as it did before: LPTx is supported by Win10-64bit, and the VirtualBox passthrough feature works too.

Good news all round.

p.s. It seems to me you could probably just have changed the port number back to LPT1 in that last dialog you show. Oh well, either way works.

[trippingslowly]

Yes, I changed everything to LPT1 and it still works.

[trippingslowly]

Spoke too soon. It does acknowledge the LPT port, but doesn't work when accessing it.