Moore LPT Problem

[Ohlala68]

Hello.
Host: Windows 7-64
Guest1: Windows XP-32

I'm work with a laser-engraving machine that works much like a printer. Its connected to the LPT1 printer port.
My software is not compatible with 64 bit winndows 7, so I figure I could use Virtual box and install my Windows XP on.
I've been able to configure all things so far. But when it comes to the LPT-port I'm stuck...(the final task, of course)

I'v reed the tutorial "Enabling and Configuring Parallel (LPTx) Ports", but I cant get it to work.

The guest op shows in device manager that there is a LPT-port, even if I disable it in VB manager.
If i delete it in XP, its just pop back after rebooting. Is this expected?

I've tried to change the name to LPT2, in both Guest and Host, without any luck.

I dont know if this help, but I tried to change the addres as well, to a number not in conflict (in divice manager in guest system),
but when I change it in VB line editor XP would not start bacause there where a conflict...

Greatful if someone could help me in this matter.
/Ola

[mpack]

You say you've read the tutorial, in which case it disturbs me that you're trying things that the tutorial emphasises make no sense, like changing the device name. The device name used to refer to the correct device on the host - that matters, and it must be correct. The name the guest OS gives it doesn't matter at all. Ditto for the fake base address and IRQ used on the guest side.

However... if you're referring to a CNC machine then IMHO it's highly unlikely to work in a VM - too much latency involved. I would suggest dual booting your host if you can't find software compatible with your main OS.

As an aside... I don't know why the home CNC market insists on using clumsy and unreliable PC parallel ports when a potential controller card - something like the Arduino say - is cheap, and can talk USB with the PC while very effectively controlling a CNC machine. Arduino's are already used in stand alone 3D printers too, and there it's controlling the motors directly, not just being a buffer.

[Ohlala68]

Sorry for my lack of knowledge in this matter.
The only reason I changed the name was to see if there were a different.(try and error)

I'm just wonder if the fact that my guest-OS finds a LPT-port that I didn't set up can interfere with the one I try to set up?

I'm not referring to a CNC machine. This is a Laserpro Mecury with some years on it. It work exactly like a printer.
The developers will however not release any drivers for W7.

I was really depressed of their non-environmental thinking. They told me to buy a newer machine.
I dont agree with this buy and throw away mentality. (That apparently also applies to more expensive things)

This is the last problem to solve, and it really feels like stumble at the finish line if this wont work.

So if you have any suggestions, after taking a deep sigh and roll your eyes, i would be greatful.

/Ola
PS. I thougt it was a bit fun setting up a VM, so I have a second guest with a Linux system on it, just to try out.

[mpack]

I'm just wonder if the fact that my guest-OS finds a LPT-port that I didn't set up can interfere with the one I try to set up?

That isn't possible. The only hardware the VM sees is the hardware created in the VM recipe. The guest won't see an LPT port at all if the recipe doesn't create one. So what makes you think that an LPTx seen by the guest is not the one you created? Presumably you've read the tutorial and understood that the name given to the device in the guest is unrelated to the name the host uses.

I already gave you my suggestion: install XP in the host in a dual boot configuration.

[Ohlala68]

Thanks for your answer.
Multiboot is something I have considered, but i'm gonna use that as a last resort, bacause they cant
run simultaneously.

First I want to know why my guest see a LPT-port.I did unistalled the LPT-port whithin the guest, then I have set the LPT-port in the recipe to off as you described.
I've checked if it took, and VM manager says:
LPT1 : Disabled
LPT2 : Disabled
After rebooting XP the LPT-port is immediately re-installed. Even with the LPT-port(s) in VM manager set to disabled.
If that not possible, then that is the problem.
What more can I do to Really disable the LPT-port in VM manager?

There is a third alternative: USB-to-Parallel-port adapter. They seem to work with printers, so if I dont get the LPT-port to work I want to test that first.

Then if THAT not work I have to......dual boot...

[mpack]

I still have my doubts that what you have works like a printer. I've looked at the website for the machine, and it looks a typical engraver to me, with live control over x and y axes. That would mean that the LPT port is used like a PIO output, and I have no idea if it would work from a VM. VMs always have high latencies which would limit how "real time" it's control of such a machine could be.

Run this command in a command console on the host:

Code: Select all

<path to VBoxManage>VBoxManage showvminfo <VM name> >showvminfo.txt

Then attach the "showvminfo.txt" file to a message here. While you're at it, attach the "VBox.log" file from the VM "Logs" subfolder too. Put both of these in the same zip.

LPT ports are not always plug and play, you can add them to the device list manually. However, if you manually delete it from the device list, and the device isn't still present for plug and play to detect and bring back, then I would expect the device to be gone for good. We'll see from the logs.

[Ohlala68]

I've done some research and you are probably right that is not like a printer drv.
I just assumed it would because it insall itself like a printer...

Well my attachments show logs, vm-info and a pic of what guest XP finds and install when I click "Add new hardware"
Hope your swedish is up-to-date

/Ola

[mpack]

My apologies. I checked your log and, as you say, the LPTs are disabled in the VM settings. I also checked my own XP VM and, as you again said, an LPT1 port is listed even though it isn't explicitly defined in my VM recipe. So, this is either a bug or it's possible that LPT1 is built into the PIIX3 chipset emulated by the VM. Strange that I've not noticed it before.

The consequence of this is that you effectively no longer get a choice about which LPTx to emulate in the VM (at least for the first LPTx). The recipe must use address 0x378 and IRQ3, hence it will appear in the guest as LPT1.

Can you show me a picture of the host device list, showing your LPTx device there?

[Ohlala68]

See my attached pic.
In your tutorial IRQ is set to 7.
Dont know if that of importance, hence interupt chould be disabled inside guest...?

[mpack]

Bah. I copied what you wrote above without checking. Now I've checked. In theory LPT1 uses IRQ7 (IRQ3 would be COM2). So IRQ7 is what you should always use. In practice it shouldn't matter a lot since VirtualBox doesn't support interrupts with LPTx ports anyway - the only danger would be in assigning a conflicting IRQ, so best stick with IRQ7.

Background: IRQs are not dynamically assignable. In the physical world there would be a track connecting a pin on the LPT chip to a specific input (IRQn) on the PC interrupt controller. If you tell the OS driver to expect a signal on a different input - and if what you've told it doesn't match reality - then the device won't work at all if it needs interrupts, and whatever is really connected to that IRQn might not appreciate the interference. If you're going to fiddle with IRQs you do need to know what you're doing.