'Nother compooter question

[Hawkmoon]

I unearthed an old multi-USB unit that was designed to be installed in the 3-1/2" floppy bay of a desktop computer. In the back, it has one standard, male USB plug for connecting to a standard USB outlet, and it also has a white connector of the type that connects to the power supply in older desktop computers. If I use just the USB plug, the unit functions as an unpowered hub. I'd like to be able to use it as a powered hub. Does anyone know of sn adapter cable that's USB male on one end and on the other end has the male connector for a power supply connector?

[230RN]

Wow, 43 reads and no response?

Can't you just stick that white line on the 5V line from somewhere in the computer?  With appropriate grounding, of course.



My limited and archaic experience is that the power supplies are -12V for the drives and +5V for the logic everywhere else.



My powered hubs all have external wall warts, but I don't think there's any reason you can't pick up a nice stiff +5V for the powered hub from somewhere else.

[Scout26]

Wow, 43 reads and no response?

"I just fly 'em, I don't build 'em."   

[Hawkmoon]

Can't you just stick that white line on the 5V line from somewhere in the computer?  With appropriate grounding, of course.

Because I don't want to open up the case on the desktop computer.

[HeroHog]

If you power the existing hub, put a diode on the power line from the USB in port to prevent power "backwashing" into the PC's MB/Cards.

[Hawkmoon]

If you power the existing hub, put a diode on the power line from the USB in port to prevent power "backwashing" into the PC's MB/Cards.

From what I understand, USB is already set up to prevent that from being an issue. However, I won't be using a USB port as input. The hub is set up to be plugged directly into a computer power supply connector. It only has two pins, so it only connects to the 5V positive and associated ground. I'm hoping to find an adapter that will allow me to power the hub from a desktop while using it with a tablet, or to plug the USB end of the adapter into a USB-to-120V adapter and run it off household current.

This is what I have -- minus the yellow and adjacent black wires and pins.



If'n I can't find such an adapter, I'll just have to scavenge an old power supply, cut one of the connectors off it, and splice it to a USB cable.

[lee n. field]

Wow, 43 reads and no response?

Can't you just stick that white line on the 5V line from somewhere in the computer?  With appropriate grounding, of course.



My limited and archaic experience is that the power supplies are -12V for the drives and +5V for the logic everywhere else.

I think I read somewhere that +/- 12V is useful mostly for archaic serial ports.  Which almost no one has anymore.

[Fitz]

it's probably USB 1.0 if it fit in a floppy slot.

As such, it'll be slow. A lot.


Get a new powered hub that's current.

[230RN]

I think I read somewhere that +/- 12V is useful mostly for archaic serial ports.  Which almost no one has anymore.

Maybe, but if I recall correctly, the old MFM and IDE drives required a big chunk of 12V power in addition to 5V for their own logic.  I think the CD drives still do, if anyone still has them.  I hate to look it up 'cause my old Que manual of repair is covered with dust.

It also strikes me that if you're going to power it just from another USB port on the machine, it will be subject to the same power restrictions of the computer's own USB ports anyhow, which won't buy you anything.  Am I right?  Am I understanding what you want to do?

[Hawkmoon]

it's probably USB 1.0 if it fit in a floppy slot.

As such, it'll be slow. A lot.


Get a new powered hub that's current.

  What fun is that?

Speed isn't an issue -- I'll only be using it to run a mouse and keyboard (on very rare occasions) on a Windows tablet computer. Yes, I know I can buy a bluetooth mouse and keyboard, but I already have a plethora of USB keyboards and mouses, and I already have this hub, so why not tinker? (As long as I'm not going to blow something up.)

And ... I hit the mother lode. Went into a box of parts leftover from 80386 days, when I used to build my own boxes, and I found three power supply splitters. One of them has already had one of the female connectors cut off, but that leaves five and I only need one. So now I just have to scrounge up a spare USB cable and start splicing.

[Hawkmoon]

It also strikes me that if you're going to power it just from another USB port on the machine, it will be subject to the same power restrictions of the computer's own USB ports anyhow, which won't buy you anything.  Am I right?

Pretty much. But I won't be using the tablet's battery to power it.

[Fitz]

What fun is that?

Speed isn't an issue -- I'll only be using it to run a mouse and keyboard (on very rare occasions) on a Windows tablet computer. Yes, I know I can buy a bluetooth mouse and keyboard, but I already have a plethora of USB keyboards and mouses, and I already have this hub, so why not tinker? (As long as I'm not going to blow something up.)

And ... I hit the mother lode. Went into a box of parts leftover from 80386 days, when I used to build my own boxes, and I found three power supply splitters. One of them has already had one of the female connectors cut off, but that leaves five and I only need one. So now I just have to scrounge up a spare USB cable and start splicing.

Because if you ever plug storage into it, or move data to said tablet, speed will be frustrating

[Hawkmoon]

You're correct, Fitz, but you're overlooking that you have a high-paying job with a computer-related company. I'm a senior citizen, getting by on social security and income from part-time jobs. If I HAD to buy a new hub I could do it but, if I can make do with something I already have, to me it's a no-brainer. If I ever need to use the hub to move data, well ... I have plenty of time, but I don't have plenty of money. Again, a no-brainer.

[Ben]

I might consider this before taking the chance on mucking something up. If you're on a budget, taking an iffy chance that fries something can be a lot more expensive than this:

https://www.amazon.com/Sabrent-4-Port-Individual-Switches-HB-UM43/dp/B00JX1ZS5O/ref=sr_1_5?s=pc&ie=UTF8&qid=1496411988&sr=1-5&keywords=usb+hub

Otherwise, if you need a hub, no guarantees until I have my next cup of coffee and get out to the storeroom to look, but I may have a spare hub in my parts box that I's happily give you for free.

[AJ Dual]

USB 1.0 is so old, and USB 2.0 has been around so long, it won't even be a matter of being "slow", but that it simply won't work with any number of devices even simple ones like mice and keyboards.

USB 2.0 came out in 2000, and IMO it becomes increasingly likely that any USB device purchased or obtained in the past 15 years or so won't even function in "slow mode" on 1.0.

[Ben]

It looks like I already gave away my old USB 2.0s. Still, <$10 for a new one (that's USB 3.0) is peace of mind, IMO.

[Firethorn]

Question:  Why can't you hook up the plug to the power supply?

Are you attempting to use it as a hub outside of a computer?

In which case may I recommend that you don't splice USB anything!

Instead, find one of those 5V wall wart USB chargers that comes with pretty much any USB device*, preferably one of the really cheap ones that come with an obviously two wire wired connection, chop the USB end off, then splice to the wires going to the molex connector.  Some microscopic wire nuts would work, though you might solder.  If you can find a matching molex plug, you could splice to that instead.  Black is ground, red is power.

That said, I agree with Ben.  Just buying a new unit is so inexpensive that it'll be the cheaper option.  The risk of damage combined with the low speeds just doesn't make mucking around with it worth it.

*I like using bluetooth ear pieces, so I have a bunch of them.  You probably got one with your last couple cell phones.

[Hawkmoon]

USB 1.0 is so old, and USB 2.0 has been around so long, it won't even be a matter of being "slow", but that it simply won't work with any number of devices even simple ones like mice and keyboards.

USB 2.0 came out in 2000, and IMO it becomes increasingly likely that any USB device purchased or obtained in the past 15 years or so won't even function in "slow mode" on 1.0.

But it already functions with a mouse and a keyboard. I just want to adapt it so it's not drawing down the tablet battery while it's doing so. It's already set up to have a 5-volt input, so all I have to do is make up a cable to feed it a 5-volt input.

[Hawkmoon]

Question:  Why can't you hook up the plug to the power supply?

Are you attempting to use it as a hub outside of a computer?

Yes.

I'm pretty certain I've said that at least twice.

[Hawkmoon]

I might consider this before taking the chance on mucking something up. If you're on a budget, taking an iffy chance that fries something can be a lot more expensive than this:

https://www.amazon.com/Sabrent-4-Port-Individual-Switches-HB-UM43/dp/B00JX1ZS5O/ref=sr_1_5?s=pc&ie=UTF8&qid=1496411988&sr=1-5&keywords=usb+hub

Not powered. I have a couple somewhat similar to this one.

Otherwise, if you need a hub, no guarantees until I have my next cup of coffee and get out to the storeroom to look, but I may have a spare hub in my parts box that I's happily give you for free.

Thanks for looking. Appreciated.

[Ben]

Not powered. I have a couple somewhat similar to this one.

Powered ones are about the same price:

https://www.amazon.com/Adapter-Transfer-laptop-Ultrabook-leedemore/dp/B01EKU1XKG/ref=sr_1_9?s=pc&ie=UTF8&qid=1496449454&sr=1-9&keywords=powered+usb+hub