"Larry" wrote in message
...
wrote in news:1148499942.560560.301020
@u72g2000cwu.googlegroups.com:

But what do you do when all you have is a RS232 port?


Er, ah, buy a computer made in the last 8 years?....

RS232 IS DEAD....really!

Not really. Only in the consumer market. 99% of the industrial computers
have serial ports because 99% of the industrial devices that need to
communicate have a serial port.

Meindert

wrote:

Look at it this way, if you have a USB port you can easily add a RS232
adapter. But what do you do when all you have is a RS232 port?


I assume were talking about laptops, you can easily add anything needed
to any PCI bus PC. On laptops most of the non-USB models will have
PCMCIA so you can add a PCMCIA dual port USB port adapter.

I think the laptops that did not have PCMCIA are all dead or in museums
by now. But I'm also sure that there is someone out there still using
them. Probably trying to get linux running on them. :)

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

On Thu, 25 May 2006 08:13:31 -0400, Jack Erbes
wrote:


I think the laptops that did not have PCMCIA are all dead or in museums
by now. But I'm also sure that there is someone out there still using
them. Probably trying to get linux running on them. :)

I got this story from a Dell laptop owner that I don't know very well,
so I can't vouch for it. He said that his new Dell has, in place of
PCMCIA, something called Dell Express. It sounds and looks a whole
lot like PCMCIA with an arbitrary form factor change to make it
proprietary. He had purchased a PCMCIA cellular modem and data plan
from T-Mobile and discovered the card didn't fit. When he called
Dell, they said that it was up to the cell company to support the
obviously superior Dell proprietary format. When he called T-Mobile,
they said they'd never heard of Dell Express and weren't interested in
it either.

I remember Dell pulling this stuff back in the day with proprietary
video card slots, so it doesn't sound entirely unlikely. Caveat
Emptor.

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"Glen \"Wiley\" Wilson" wrote in
:

When he called
Dell, they said that it was up to the cell company to support the
obviously superior Dell proprietary format.

Exactly at the point in time when he should have packaged it back up and
returned it to its source for a full refund.....(c;

Gateways have a PCMCIA slot......and 4 USB ports...(c;

On Thu, 25 May 2006 18:53:06 -0400, Larry wrote:


Exactly at the point in time when he should have packaged it back up and
returned it to its source for a full refund.....(c;

Concur.

Gateways have a PCMCIA slot......and 4 USB ports...(c;

Just curious, if you have one of the 4 USB units, does it have enough
power at the ports to drive 4 USB-powered devices at the same time? I
have a USB-powered hard drive; it works fine on some laptops, not at
all on most of them. When I use an external power supply everything
is fine.


__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at world wide wiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/

"Glen \"Wiley\" Wilson" wrote in
:

Just curious, if you have one of the 4 USB units, does it have enough
power at the ports to drive 4 USB-powered devices at the same time? I
have a USB-powered hard drive; it works fine on some laptops, not at
all on most of them. When I use an external power supply everything
is fine.


I'm using my US Modular 2.2GB USB pocket hard drive from the USB port on
the Gateway with no problems. The drive is $53 from any WalMart
electronics department. It looks like a miniature silver hand warmer with
the silver cap on the USB plug. It also comes with a 2' USB extension
cable in case you have trouble plugging the drive directly into the port on
your system. It plugs direct to any port in the side of the Gateway. It
uses quite a bit of power in my application, watching a new movie at my
breakfast diner, for instance. It gets very warm under continuous access
like this, but I've never heard a complaint from the big 15" notebook's
battery pack.

My 400GB external USB hard drive gets its power from an AC power brick, not
the USB port. Its USB port is the square one without the power drain. I
wouldn't expect any computer to run the 400GB big hard drive and all those
LEDs and cooling fan. USB doesn't have that kind of power output.

On Fri, 26 May 2006 21:13:19 -0400, Larry wrote:

My 400GB external USB hard drive gets its power from an AC power brick, not
the USB port. Its USB port is the square one without the power drain. I
wouldn't expect any computer to run the 400GB big hard drive and all those
LEDs and cooling fan. USB doesn't have that kind of power output.

I try to avoid having AC powered accessories for the laptop. The
typical wall warts are obnoxious to deploy, tie up 2 plugs on a power
strip, and are heavy and bulky to schlep. I had 3 laptop HDs
(40-80GB) laying around so I picked up an enclosure. It's just an
IDE-USB adapter in a metal case with a padded leather wallet to carry
it in. The whole thing is a bit smaller than my old handheld. 1 LED,
no fan, with a USB cable. The USB cable has a neat wrinkle - there's
a "Y" in the cable so you can plug the drive into 2 ports to get
enough power if one port doesn't work. Works fine, but I'd rather not
waste the extra port.
__________________________________________________ __________
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To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
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Glen "Wiley" Wilson wrote:

snip
Just curious, if you have one of the 4 USB units, does it have enough
power at the ports to drive 4 USB-powered devices at the same time? I
have a USB-powered hard drive; it works fine on some laptops, not at
all on most of them. When I use an external power supply everything
is fine.

The USB specs say that a USB port can provide 500mA for the device that
is plugged into it. If the advertising says that the drive can take its
power from the USB port it should mean that the drive draws less than
500mA at max draw.

The engineering on the laptop should be that the conductors for each
port are adequate to the rated max and that the USB bus is adequate to
all the ports drawing the max (four ports, would be 2A).

If your drive works on some laptops but not on others, it must be
monitoring the available power or the load on the USB bus and electing
not to participate. I guess it could do that by measuring the voltage
drop on the USB bus?

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

On Sun, 28 May 2006 08:41:04 -0400, Jack Erbes
wrote:

The USB specs say that a USB port can provide 500mA for the device that
is plugged into it. If the advertising says that the drive can take its
power from the USB port it should mean that the drive draws less than
500mA at max draw.

Thanks, I didn't remember the exact number. I haven't checked, but
I'd bet the IBM drive I'm using now is more like 1 amp. I have a
Fujitsu drive that is 550mA; I should give it a shot.

The engineering on the laptop should be that the conductors for each
port are adequate to the rated max and that the USB bus is adequate to
all the ports drawing the max (four ports, would be 2A).

Yes, it should be that way. I'd been thinking the problem was that
some ports didn't meet the spec. Now I wonder if it isn't that some
ports exceed the spec. Those work for me, the ones that merely meet
the spec don't.

In the past, when using an unpowered external USB hub with a couple of
devices, I've gotten a Windows message saying that I'm exceeding the
power availabilty of the port. I don't know exactly how that message
gets triggered, but I've never seen it when using this drive.


If your drive works on some laptops but not on others, it must be
monitoring the available power or the load on the USB bus and electing
not to participate. I guess it could do that by measuring the voltage
drop on the USB bus?

Perhaps, but I didn't supply all the details. The drive spins up but
makes a clicking noise louder than a normal seek. It might be trying
to calibrate the heads or returning to rest position repeatedly. I
think it's actually trying to participate, but failing.

__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at world wide wiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/