Parallel port from docking station

[Squarewave]

In my quest to get a working parallel port for using my older eprom programmer, I tried a docking station on a Dell laptop we have at work. Windows sees the port as a parallel printer port, but I can't get it to communicate with the tester.

Am I right then in assuming that via a docking station, it isn't mounting as a full IEE1284 port?

[Psi]

It's highly likely that it's a winport. The docking station will connect to the laptop over some form of USB and a full IEE1284 port needs proper access directly onto the system bus.

WinPorts are useless for anything but printing. They're basically a port with a driver that hooks into the windows printer system.

If you can find a PCMCIA/CardBus printer port adaptor, and laptop that takes it, those should be a full IEE1284 port.
You can also buy PCI / PCie cards that provide a full IEE1284 port, but you also come across some that don't, so it's a bit of a crap shoot. 

[Squarewave]

Yes I guess it appears to be the case, it was worth a go I suppose, ruled that one out.

[Gyro]

If there's no parallel port socket on the laptop itself, it is pretty unlikely that there will be an ISA/PCI bus interface to the docking station. I'm only really familiar with Thinkpads (apart from really old Win9x ones), and they do carry the full built-in parallel port signals through the (very wide) underside docking connector.

I suspect the S/W is looking for an original LPT1/2 port (I/O address 0x3BC / 0x378), possibly even bit bashing it.

[MarkL]

Some of the older Dell laptops have real parallel ports on the docking station.  For example, I use a Dell Precision M4400 with the docking station to control a GALEP-4 parallel programmer.  Not sure how far retro you're willing to go, but they are still widely available.

[Gyro]

That's useful to know. On Thinkpads, T43 and earlier have 'proper' parallel ports.

[Squarewave]

In fact, I've got a Gallep 4 somewhere.

So, this laptop is a Dell Latitude E7270, windows sees the port and lists i/o addresses which can be changed, but alas won't work.

Hopefully I'll have my other laptop working soon.

[Psi]

Also consider that windows blocked direct hardware access to ports from, I think, winXP and on.

So if your eprom programmer app is trying to talk directly to the hardware port addresses itself (rather than going through windows API) it won't work on a modern OS even if you have a proper printer port.

Win2000 and before were ok and I think there was an easy hack to get direct hardware access working in 32bit winXP but not 64bit

So consider that you may need to install the right windows version as well as getting a compatible printer port.

[Squarewave]

Also consider that windows blocked direct hardware access to ports from, I think, winXP and on.

So if your eprom programmer app is trying to talk directly to the hardware port addresses itself (rather than going through windows API) it won't work on a modern OS even if you have a proper printer port.

Win2000 and before were ok and I think there was an easy hack to get direct hardware access working in 32bit winXP but not 64bit

So consider that you may need to install the right windows version as well as getting a compatible printer port.

Do you mean that an older version of Windows still won't work with this docked port?

I know on another laptop I have, with a parallel port on the back, with XP, it does work, but that laptop is terribly slow.

[Psi]

I did some checking and i believe even win XP 32bit used to block direct hardware access.
So that suggest your app doesn't need that, so you probably don't have to worry about the direct hardware access issue and which OS to use.

[TERRA Operative]

Some of the older Dell laptops have real parallel ports on the docking station.  For example, I use a Dell Precision M4400 with the docking station to control a GALEP-4 parallel programmer.  Not sure how far retro you're willing to go, but they are still widely available.

My later model Dell Precision 7520 laptop still retains the same docking port as the M-series (I previously had an M4800) and the Parallel/Serial ports on my E-Port Plus II dock appear to be real, and have always worked as such as far as I have used them.

[Squarewave]

Some of the older Dell laptops have real parallel ports on the docking station.  For example, I use a Dell Precision M4400 with the docking station to control a GALEP-4 parallel programmer.  Not sure how far retro you're willing to go, but they are still widely available.

My later model Dell Precision 7520 laptop still retains the same docking port as the M-series (I previously had an M4800) and the Parallel/Serial ports on my E-Port Plus II dock appear to be real, and have always worked as such as far as I have used them.

That's interesting, as your 7520 is a similar generation to my Dell 7270 laptop and I think that's the same dock as what I'm trying to use. So I wonder if there's something else I need to do?

Or do you mean your parellel port on the dock worked with the M4800, or have you tried it with the 7520 also with test equipment?

[Postal2]

Also consider that windows blocked direct hardware access to ports from, I think, winXP and on. ...

True. In order not to use a special driver, you can run the program "Sandra" and do what you need without closing it. Perhaps this effect will be from other computer check programs.

.... I know on another laptop I have, with a parallel port on the back, with XP, it does work, but that laptop is terribly slow.

The thing is that it is impossible to organize a port with ISA numbers via PCI. If a program accesses the port directly, bypassing the LPT table, you will be forced to use drivers that perform "patch on the fly", or the chipset must have special tools for this. "Patch on the fly" is dangerous for various reasons, programs will try to block it, causing it to freeze, and antivirus will delete it.

You can look at the LPT driver properties for the resources occupied and try (for a PCI connection) changing the port number to 0x378. I may be wrong, but it is quite possible that switching may depend on the virtualization type supported by the processor.

[Gyro]

This is bringing back distant memories. I remember there used to be a DLL that could be used for direct port access on XP, a quick search brings up Inpout32.dll (which matches my recollection). I can't remember whether it works natively without changing apps, but it's worth reading up on.

Edit: Nope, it was just for self-written code port access.

[Postal2]

.... Edit: Nope, it was just for self-written code port access.

These drivers had a configurator that specified which ports to open. Computer testing programs usually opened everything for everyone.
Once upon a time, I was scolded for using a driver to access LPT, when direct access was fashionable. And it was hard for me to explain to people that this approach was wrong. I just took the driver and used it (attached file). But years passed, systems were updated, and the driver was no longer suitable. They started telling me to make a driver, but I had no desire to study WinDDK for this. Then an experienced student (probably not a student now) developed a universal driver for any system, which also had a digital signature.
https://github.com/dmitrystu/LptDrv

This is bringing back distant memories. ....

My program for the LPT port can be used right now under Windows 10x64. But if I had used direct access, this opportunity would not have existed.

[Squarewave]

So what are we saying, there's a way? Or should I give up and just use my older laptop?

[Postal2]

So what are we saying, there's a way? Or should I give up and just use my older laptop?

Not "give up", but just use the old laptop as well. This is normal for a smart person. I have 9 computers for different purposes, and an endless number of SSDs with installed systems that I can instantly start. I do not understand some people with their desire to cram everything into one device.

Some devices have flaws that you can't overcome. You just need to adjust the scenario of using such devices. For example, I have a laptop that wakes up from hibernation with 3 cores instead of 4. I can spend a lot of time trying to fix this, create a million threads on different forums and distract people from more important things with my nonsense. Will it be productive?

[amyk]

I pulled up the schematic for your laptop and the dock connector has LPC going to it, so depending on what's on the other side in the dock (probably a super I/O?) you should be able to get a real parallel port out of it.

The easiest way to confirm whether it's a real port is to boot into DOS, stick an LED and a resistor on one of the data pins on the port, and use the DEBUG utility to blink it.

[Squarewave]

So what are we saying, there's a way? Or should I give up and just use my older laptop?

Not "give up", but just use the old laptop as well. This is normal for a smart person. I have 9 computers for different purposes, and an endless number of SSDs with installed systems that I can instantly start. I do not understand some people with their desire to cram everything into one device.

Some devices have flaws that you can't overcome. You just need to adjust the scenario of using such devices. For example, I have a laptop that wakes up from hibernation with 3 cores instead of 4. I can spend a lot of time trying to fix this, create a million threads on different forums and distract people from more important things with my nonsense. Will it be productive?

Well that's completely ruled me out.......

[Squarewave]

I pulled up the schematic for your laptop and the dock connector has LPC going to it, so depending on what's on the other side in the dock (probably a super I/O?) you should be able to get a real parallel port out of it.

The easiest way to confirm whether it's a real port is to boot into DOS, stick an LED and a resistor on one of the data pins on the port, and use the DEBUG utility to blink it.

Ah, that sounds interesting.

As I'm not a smart person, which pins should I go into and what are the DOS commands? Thanks.

[Gyro]

Silly question, but have you checked the BIOS settings for the parallel port? There is a BIOS setting for output only, EPP, ECP on laptops with built-in port that overrides everything in Windows - you wouldn't be able to select ECP if the BIOS was set to EPP. Maybe try booting to BIOS with the laptop already docked in case the setting is normally hidden. I assume you used Device Manager to determine that it wouldn't mount as a full IEE1284 (ECP) port.

[Squarewave]

Yes, the only options are PS2, AT and ECP. It should work under ECP. The port options are still there when not fitted to the dock.

[Gyro]

If the port options are there in BIOS, that's strong confirmation that it is a true parallel port. Try all three settings.

[Squarewave]

I tried all three, none worked. I'll need to run some other tests on the port in that case.

[Gyro]

Damn, you sound so close! There used to be parallel port loopback tests (just the first hit)... https://electronics.stackexchange.com/questions/79774/how-to-do-a-loopback-test-of-a-parallel-port


P.S. It makes sense that it would be a full port, a Dell would have been able to work with parallel port dongles for CAD packages etc.