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usb powered external cd/dvd drive

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Anonymous
a b D Laptop
September 22, 2004 6:24:09 PM

Archived from groups: comp.sys.laptops (More info?)

I am looking for a compact external CD or DVD drive (no need for write
capability) that is powered SOLELY by the laptop, preferably via USB
port only. I don't want to need to use a 120V cube.

Storix used to make one (7236 and 9229, I think were the numbers) but
it would appear that they have folded up shop. mystorix.com has
disappeared and a quick google search for the two drives comes up with
nothing.

Archos makes some but appear to be un-necessarily bulky. The specs
are also a bit confusing in that with similar looking drives, some
need a 120V cube and others do not. Others don't specify. Which ones
fit my specification for power?

I am looking at the IBM X40 and don't want to use the proprietary
connector that IBM uses. Besides, the price is a bit high.

Conway Yee
Anonymous
a b D Laptop
September 23, 2004 5:23:42 AM

Archived from groups: comp.sys.laptops (More info?)

> Archos makes some but appear to be un-necessarily bulky. The specs
> are also a bit confusing in that with similar looking drives, some
> need a 120V cube and others do not. Others don't specify. Which ones
> fit my specification for power?

None of them. No CD-ROM mechanism I have seen so far meets the nominal
500mA USB current limit, at least for surge. All of them can require
more current when seeking. Here for instance is the typical current
requirement for a 24x, laptop-style CD-ROM:

DC Current < 800 mA read (typical at Outer Diameter)
< 900 mA write (typical at Outer Diameter)
< 1600 mA (maximum excluding spike current < 1 ms duration)
< 100 mA (low power mode)
< 70 mA (sleep mode)
Total Drive Power
(standby mode) < 70 mA

Spikes can be over 2A.

Laptops also frequently have more stringent current restrictions than
normal USB hosts. They are, on occasion, implemented the same way as
bus-powered hubs, which means a max of 100mA. So even if you do get an
(out-of-spec) USB-powered drive, you will likely find that it might work
on some desktops, but won't work on your laptop at all unless you use a
powered hub. As an example of this, my laptop will not work with
bus-powered USB hard drives.
Anonymous
a b D Laptop
September 23, 2004 5:48:06 PM

Archived from groups: comp.sys.laptops (More info?)

Conway Yee <yee@bronze.lcs.mit.edu> wrote in message news:<bqwsm9ajh6e.fsf@bronze.lcs.mit.edu>...
> I am looking for a compact external CD or DVD drive (no need for write
> capability) that is powered SOLELY by the laptop, preferably via USB
> port only.

Take a look at:
http://www.micro-solutions.com/
Related resources
Anonymous
a b D Laptop
September 24, 2004 2:04:31 AM

Archived from groups: comp.sys.laptops (More info?)

See this one:

http://www-132.ibm.com/webapp/wcs/stores/servlet/Produc...

If IBM has it, I am sure there are other brands that sell similar drives for
less.



"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote...
> > Archos makes some but appear to be un-necessarily bulky. The specs
> > are also a bit confusing in that with similar looking drives, some
> > need a 120V cube and others do not. Others don't specify. Which ones
> > fit my specification for power?
>
> None of them. No CD-ROM mechanism I have seen so far meets the nominal
> 500mA USB current limit, at least for surge. All of them can require
> more current when seeking. Here for instance is the typical current
> requirement for a 24x, laptop-style CD-ROM:
>
> DC Current < 800 mA read (typical at Outer Diameter)
> < 900 mA write (typical at Outer Diameter)
> < 1600 mA (maximum excluding spike current < 1 ms duration)
> < 100 mA (low power mode)
> < 70 mA (sleep mode)
> Total Drive Power
> (standby mode) < 70 mA
>
> Spikes can be over 2A.
>
> Laptops also frequently have more stringent current restrictions than
> normal USB hosts. They are, on occasion, implemented the same way as
> bus-powered hubs, which means a max of 100mA. So even if you do get an
> (out-of-spec) USB-powered drive, you will likely find that it might work
> on some desktops, but won't work on your laptop at all unless you use a
> powered hub. As an example of this, my laptop will not work with
> bus-powered USB hard drives.
>
Anonymous
a b D Laptop
September 24, 2004 2:04:32 AM

Archived from groups: comp.sys.laptops (More info?)

"Edmund F" <kybear@iname.com> wrote in message news:<ciumir$284f$1@news.hgc.com.hk>...
> See this one:
>
> http://www-132.ibm.com/webapp/wcs/stores/servlet/Produc...

Interesting that nowhere does it state what the current requirements
are. However, IBM does say: "Limitations - Some configurations may not
be supported.". This may mean that it only works on machines that
don't properly implement current-limiting on their USB ports.

Also note that the availability on that IBM store site is "within 2
weeks" yet the product was announced in 2000. It's also designed for
use with the TP240X, which was discontinued in 2000 or 2001. There are
no drivers available for it online.

IBM doesn't make their own CD-ROM drive mechanisms; I have had only
Panasonic drives (and I think once a Samsung?) in IBM laptops. I'm
pretty familiar with what Panasonic has to offer, as I have had to
design their CD drives into embedded systems - they don't currently
have anything that will operate guaranteeably from 500mA.
Anonymous
a b D Laptop
September 24, 2004 12:19:58 PM

Archived from groups: comp.sys.laptops (More info?)

That CD-ROM drive is actually quite slow by modern standards that it reads
at 10x. Maybe that partly explains why it doesn't need external power?

As for driver support, a friend of mine uses that drive and it doesn't need
install additional driver in Windows XP.



"Lewin A.R.W. Edwards" wrote...
> "Edmund F" <kybear@iname.com> wrote in message
news:<ciumir$284f$1@news.hgc.com.hk>...
> > See this one:
> >
> >
http://www-132.ibm.com/webapp/wcs/stores/servlet/Produc...
>
> Interesting that nowhere does it state what the current requirements
> are. However, IBM does say: "Limitations - Some configurations may not
> be supported.". This may mean that it only works on machines that
> don't properly implement current-limiting on their USB ports.
>
> Also note that the availability on that IBM store site is "within 2
> weeks" yet the product was announced in 2000. It's also designed for
> use with the TP240X, which was discontinued in 2000 or 2001. There are
> no drivers available for it online.
>
> IBM doesn't make their own CD-ROM drive mechanisms; I have had only
> Panasonic drives (and I think once a Samsung?) in IBM laptops. I'm
> pretty familiar with what Panasonic has to offer, as I have had to
> design their CD drives into embedded systems - they don't currently
> have anything that will operate guaranteeably from 500mA.
Anonymous
a b D Laptop
September 24, 2004 12:19:59 PM

Archived from groups: comp.sys.laptops (More info?)

> As for driver support, a friend of mine uses that drive and it doesn't need
> install additional driver in Windows XP.

Right, because it implements standard USB-Storage interface. However IBM
specifically states they provide "recovery" (i.e. DOS) drivers for it.
Since these are unavailable, I wonder if this is a product that is
semi-vaporware - pulled off the market quickly.
Anonymous
a b D Laptop
September 26, 2004 5:59:14 AM

Archived from groups: comp.sys.laptops (More info?)

"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:D mK4d.12650$n16.3714@newsread2.news.atl.earthlink.net...
>
> Right, because it implements standard USB-Storage interface. However IBM
> specifically states they provide "recovery" (i.e. DOS) drivers for it.
> Since these are unavailable, I wonder if this is a product that is
> semi-vaporware - pulled off the market quickly.

I just checked and the DOS drivers *are* available:
http://www-1.ibm.com/support/docview.wss?uid=psg1MIGR-4...

The drive itself is also in stock.

The drivers are from Teac, which implies the drive is too.

Found another drive that claimed to be USB bus-powered:

http://prodb.matsushita.co.jp/product/info.do?pg=04&hb=...

Disclaimer says (loosely translated):
'Depending on the computer's ability to supply USB bus power, there are
times when the drive cannot operate on USB bus power. When used with other
USB peripherals, please use the AC adapter. When PC boards or PCMCIA [sic]
[USB] cards are used, there are times when the drive cannot operate on USB
bus power.'

In the US, Dynamism seems to be the only place selling it (ie, grey import).

JL
Anonymous
a b D Laptop
September 26, 2004 8:27:19 PM

Archived from groups: comp.sys.laptops (More info?)

"Conway Yee" <yee@bronze.lcs.mit.edu> wrote in message
news:bqwsm9ajh6e.fsf@bronze.lcs.mit.edu...
> I am looking for a compact external CD or DVD drive (no need for write
> capability) that is powered SOLELY by the laptop, preferably via USB
> port only. I don't want to need to use a 120V cube.

Buslink D-RWD8-U2.

Officially it comes with an adapter, but at least for reading it works off
the USB cable YMMV. I've used it with a Sharp MM10 Thin and Light, as well
as with desktops. I haven't tried it writing, and I suspect that it may
exceed the USB ports ability to supply power. Officially, USB is limited to
500mA.

On some notebooks, they have one higher current port, with an extra hole for
a key next to it, and they key the cable to fit only in that port.
!