Dell Latitude CSx J500XT (CSx H500XT)

System Requirements:

  • Dell Latitude CSx

The Problem:

Welcome to wonderland Alice!

I was given a Dell Latitude CSx J500XT (Post Screen) – a Latitude CSx H0XT (BIOS) – and wanted to see what this slim line pup was made of. This article simply outlines my playing with the device.

More Information:

It’s quite a natty little device for its age, very light and slim line and it has some teeth given its PIII coppermine back end.

When I originally got my hands on the system, it was billed as being non-functional, was equipped with the following specification:

  • PIII 500MHz
  • 128MB PC100 DIMM
  • 20GB Hitachi Hard Drive
  • Windows NT 4.0 Workstation

Windows 2000

A system with a PIII and 384 MB of RAM can hack something a little more modern than NT 4.0 (not that I have anything against NT 4.0 mind), so I figured that I would try Windows 2000 SP4 (see my slipstream guide) on the system. There was a slight problem however.

No CD/DVD Drive. This system is slim line, and cannot accept the usual Dell modular bay hardware, instead it is supposed to have an external bay device caddy for the drive and a cable that attaches to the port replicator on the right hand side – neither of which I had. Incidentally, I have since discovered that the part number required is 10NRN External Media Cable.

I pulled the disk out and threw it into a Latitude CPi, wiped the disk, partition tables and FDisk /mbr’d the system. I then copied the i386 folder from the slipstream disk onto the device and threw it back into the CSx. Would it boot? Like hell!

To cut a very long story short, I had to perform some rather deep scrubbing of the 512 KB boot sector on the disk, because for some reason unbeknownst to me, none of my standard disk tools seemed able to scrub the boot sector on the hard disk, and the install process that embeds NTLoader onto the disk wasn’t able to over-write it either! So one assumes that the disk must be damaged

  • ChkDsk
  • ScanDisk
  • Partition Magic
  • SeaTool for DOS
  • Replacing the hard disk and installing a known working Seagate of equal capacity

Nothing after purging that drive using all of these standard tools and fixes.

  • FDisk
  • PowerQuest Partition Magic
  • Acronis
  • Windows 2000 Setup

None of these could get it. To cut this story short, in the end I discovered a nice little utility that blitz ‘d the disk’s first few sectors at the hardware level and it whirred back into life, installing Windows 2000 in a comfortable amount of time and working very nicely.

Grab the chipset driver and the graphics drivers from the Dell website and get them on the install – the NeoMagic driver offers you a little more control over the TV output and screen settings on the motherboard.

Windows XP

You have to try don’t you. I used a PIII 733 Dell Inspiron 3800 for several years with Windows XP and 384 MB RAM, so theoretically the performance level shouldn’t be that much different, particularly given that I have installed a larger, faster hard drive in the CSx.

Again, the installation had to take place using a local system i386 install process from a DOS prompt – hooray for my new multi-mode (ATA, 2.5″ ATA and SATA) to USB hard drive converter.

RAM Upgrade

The first thing that I always do (of course) is update the firmware of my equipment, so I hit the BIOS up to the latest A13 and found and loaded a firmware update for the Hitachi hard drive in the device.

According to Dell, Crucial and Kingston, the maximum RAM that this system can take is a rather unusual 320 MB (256 MB + 64 MB). Well, I had a 256 MB DIMM and a box full of 128’s lying about, so I threw them in there, expecting it to beep code at me, and…

Photograph of the system BIOS With 384MB RAM
Here the device is, posting and happily running with 384 MB (256 MB + 128 MB) in the BIOS.

I then came into possession of another 256MB chip, this time a PC133 CAS latency 3 chip (you can tell by the chip label, CL3 chips are PC133-333-520). This refused to POST at all, so assumed that it had made the maximum RAM, however fortuitously I came into another 256MB chip, this time a CL2 chip (PC133-322-620) and tried again.

The Latitude CSx H500XT posted with 512MB of PC133, loaded Windows XP and to this day still runs happily with 512MB and XP SP3. Proving that you can’t really rely upon the manufacturer or RAM supplier sites to have a clue about exactly what systems are capable of to begin with.

The Processor

Dell shipped this notebook with a:

  • Intel Mobile Pentium III
  • 500MHz
  • 100MHz FSB
  • 256 KB L2 Cache
  • Specification Finder Code: SL43P

I, on the other hand, happened to have one of these (a x86 Family 6 Model 8 Stepping 3):

  • Intel Mobile Pentium III
  • 650MHz
  • 100MHz FSB
  • 256 KB L2 Cache
  • Specification Finder Code: SL442
sSpec Number SL43P SL442
CPU Speed 500 MHz 650 MHz
Bus Speed 100 MHz 100 MHz
Bus/Core Ratio 5 6.5
L2 Cache Size 256 KB 256 KB
L2 Cache Speed 500 MHz 650 MHz
Package Type Micro-PGA2 Micro-PGA2
Manufacturing Technology 0.18 micron 0.18 micron
Core Stepping PB0 PB0
CPUID String 0683 0683
Thermal Design Power 16.8 w 21.5 w
Thermal Specification 100c 100c
VID Voltage Range 1.6 v 1.6 v / 1.35 v

Photo of the PIII SL422 CPU Die

It doesn’t seem illogical to assume that this CPU would operate in the Latitude, and one would be correct with that sentiment… with a but. The system does not seem to actually acknowledge the extra megahertz that it has in it. According to the Windows System Information tool, the operating system is operating at 489 MHz (Exactly the same as with the original 500 MHz chip in it).

004 003

Photograph of the Jumper matrixPhoto of the jumpers location on motherboard
The Intel Processor Frequency ID utility identifies the processor as running at 500MHz, but curiously also states that it was expecting 500MHz to begin with! I find this rather odd.

Finally, the Dell BIOS does not properly detect the processor. On the initial overview screen (shown at the top of this article), the processor is listed as:

  • Intel(R) SpeedStep(tm) 0/0 MHz

Perhaps more interestingly, the configuration option for the CPU boot compatibility mode now toggles between compatible and “0 MHz” – quite a feat!

This tells me that there must not be any headroom in the Dell BIOS programming for additional microcodes on this system – or that the multiplier has been hard locked on the board. I had a look around the motherboard and there is not much in the way of jumpers to configure, the only ones that are visible on the top side can be seen in the photo on the right (click to enlarge). I was not willing to fully disassemble the system and check the back of the board, however knowing Dell, there would not be a hardware option to change the multiplier.


I did of course experiment with tripping the four J8 pins, and each time, without fail, and no matter what the combination, the system would not boot – or even power on. I have no idea what this header is for, however it doesn’t appear to do anything to the processor. If anyone else is looking for information on upgrading the processor in the Latitude CSx series, then there is your answer, unless you happen to know of a BIOS hack/trick that can be used to modify the multiplier and get the system past the 500MHz barrier.

I have left the 650 MHz processor in the Latitude, it runs quite well with it in, with no obvious thermal issues or instability (and you never know your luck, the hardware monitors could be reporting incorrectly).

If you would like a photo of the top-side of the motherboard – click here.