Introduction Configuration Subsystems Installation Recommendations

Dell Inspiron 6000d

James F. Carter <>, 2005-03-30

Here are some suggestions for how to improve the Dell Inspiron 6000d:

Random number generator

There isn't one, hiss, boo. In the modern world it's essential for laptop users to use good cryptographic keys for secure TCP (TLS) connections, for VPNs, and for protecting data when the laptop is stolen. Just today (2005-03-29) a UC Berkeley staff person had his laptop stolen with unencrypted personal information on it about over 90,000 graduate school applicants. Dell should do their part to help users protect their data properly, by including the hardware random number generator on every machine, particularly on laptops. You did it on the Dimension 4600; why not on the Inspiron 6000d?

Secure Digital slot

Given that USB flash memory devices are so cheap, I'm surprised that you used the Ricoh R5c822 rather than a USB interface. With USB you would not need a special driver; both Windows and Linux would be able to use the SD chip with existing drivers and user training. In any case, you should announce the chip type so the Linux driver people can get it supported.

A good feature of the SD slot is that the card stays mostly inside the machine, unlike a USB device which sticks out and is easily damaged. This arrangement should be retained in the future.

ACPI Fan and Thermal Zone

The fan tachometer, the thermal management setpoints, and all the thermal sensor readings should be exported in the ACPI DSDT, just like on a server. Users should be allowed to set these within reasonable limits. In particular, for some people even the very quiet low speed fan may be a problem, and they should have the choice of totally passive cooling.

Temperature Sensor

The datasheet for the ICH-6PM chipset says that the internal temperature sensor is accurate to 13 C, which is not particularly accurate. I would be willing to spend a few bucks extra for a thermistor on the mobo (which doesn't monitor the chip temperature but does know about blocked airflow or high ambients); I know a model that is linear to 2 C over 0 to 100 C and is not that expensive. And the description suggests that they may be cueing on the raw forward voltage of the sensor diode, which would have major issues of manufacturing tolerances. Why isn't Intel using the voltage difference at two different currents, which is exactly linearly proportional to the absolute temperature, with no adjustable parameters?

Power Connector

It sticks out two inches from the back of the machine, right into this person's knee, so it's definitely vulnerable to putting damaging torque onto the motherboard. Certainly a right-angle connector should be used, and given the possibility of damage to the mobo, you might consider pro-actively replacing the cable or giving everyone a cable extender with a right-angle bend. I'm certainly going to look for one at my local computer store.


The case of a laptop is important both functionally and in selling the machine to someone who sees the machine on another owner's lap. Here is a list of case issues that need to be worked on.


Qualify and offer 533 MHz memory. According to a co-worker, Dell is notorious for offering fast CPUs and chipsets but slow memory. His speculation is that Dell is very value conscious and they need to test the tolerances and error rate of the memory they offer, from whatever vendor they currently are getting the lowest price from. This takes work, and in some cases the test program is not done on time or is never done, so the faster memory cannot be offered. Dell should make a policy that if a particular FSB speed is offered, matching memory should also be available, and people should be encouraged to get it. Of course Dell will charge extra for the faster memory.

Passive Illumination

The display panel uses 6 watts of power, most of which goes to the lamp. At this power level, when the machine is used outdoors the screen is just barely readable. The human visual system is designed to look at targets illuminated by ambient light, e.g. prey, predators, or other people. It has automatic color and brightness compensation for varying ambient light, such as sky brightness vs. direct sun vs. tungsten lamps. It is not designed to achieve its goals on self-luminous objects, limited in nature to the sun, moon, stars and campfires. PDAs like the Sony Treo have a passive display viewed by the ambient light, so they are equally readable and have equally good color rendition in direct sunlight versus dim artificial illumination, and (important for mobile devices) there is zero power to the lamp unless you turn on the optional edge lighting. Dell should commission a large format passive display panel and use it in their laptops.

The only problem with the display on the Treo is that it has 33% reflectance max (according to the Samsung data sheet for the panel). But a gray-looking readable screen is a whole lot better than 185 nits of active illumination in a full sunlight environment. I'm not sure if 33% is an intrinsic limit; if the panel vendors knew that Dell was getting serious about passive laptop screens, they might have an alternate technology allowing the reflectance to be raised substantially.

Battery Charging

According to the ACPI BIOS, when the battery is being charged and it reaches about 95% of nominal charge, the regulator gates the charging current on (2 amps) or off (zero) until the charge is full. According to Sony, the correct way to charge a LiIon battery is to feed current into it so it will charge in the time specified on the data sheet (1 hour for polymer technology), but when the voltage reaches the maximum allowed value, 4.20 volts per cell, which happens at about 80% charge, the voltage should be held constant. The battery will then reach 99% of full charge in another hour. While gated charging is probably not harmful as long as the voltage stays below 4.20 volts, likely it takes longer to charge the battery than voltage regulated charging.

Rugged Version

Military users, field repair people, field biologists, and families with small children and boisterous pets have special needs in computers. You could probably sell a ton of low-end machines to the same market segment that buys Barbie's Computer, and the New Mobile Army for the Information Age is going to need a lot of higher-end, higher-profit machines. Here is a short list of features that would make the machine more rugged. I recommend many of them for the normal models as well.

Introduction Configuration Subsystems Installation Recommendations