Upgrading the Palm m100 to 8MB DRAM

Background
My trustworthy Palm Pilot Pro was showing its age, and has already gone through 2 memory upgrades, button replacement, and screen replacement. After the most recent failure, I purchased one of the new Palm m100 units to replace it.

I debated between just buying a Vx vs. an m100 for quite some time. The Vx is established, fits in a shirt pocket, and generally looks "classy". I finally opted for the m100 over the V / Vx for several reasons:

1) It is less than half the cost

2) Its hinged cover makes it easier to carry in my pants pocket or labcoat. Things in my shirt pocket fall out when I lean over a patient.

3) The plastic digitizer screen should be more resistant to impact and flexing (sitting with it in my pants pocket) than the glass III or V units

4) If rule #3 fails, see rule #1

The only real drawback I perceive the m100 having relative to the Vx is lack of memory. Fortunately, the procedure for upgrading the Palm III to 8MB described by Tim Charron can be adapted to the Palm m100, and in some ways is somewhat easier since there are fewer wires.

WARNING: What follows is a description of my efforts and results. I share the information freely so that those who are technically inclined may benefit. I make no claims about your ability to perform this mod. Unless you are proficient at surface-mount soldering, do not even consider attempting this.

Accessing the innards
First, remove the snap-in hinged cover by gentle prying straight out of the back with a small flat-bladed screwdriver.

Next, remove the snap-on coverplate by gently prying back the latch behind and below the power button, then hinging forward and removing.

The m100 sans snap-on cover:

Next, turn the unit onto its back and remove the four microTorx screws. Unlike the Palm V / Vx, there is no hotmelt glue sealing the m100, just the four micro-Torx screws. I purchased a micro-Torx set from Jensen Tools (www.jensentools.com), SKU 289-080 "Micro Torx Screwdriver Set, 4 pc.", for $21 plus shipping. It arrived as one universal handle and 3 interchangable blades (one was missing), but the largest of the 3 present blades easily opened the Palm. No glue, no stickers, no hassle.

The m100 readily separates into two pieces, one with the batteries, and one with everything else. There are no wires connecting the battery unit to the main unit, so the battery half can be laid aside.

The Mod
Identify the 2MB memory chip in the upper left-hand corner of the board.

On my unit it was labeled M51V18165DSL-6. Carefully unsolder it from the board. I used a RadioShack 15 watt pencil iron and their DeSoldering Braid, part # 64-2090, to remove the solder from the pins of the chip. Gently pry the chip up with a small, thin flat-blade screwdriver, applying spot heat as needed to get the legs free. I used an eyeglass repair screwdriver to pry with.

There is one 0 ohm jumper at the indicated spot to be removed, and one "double jumper" which needs to be moved from one set of pads to another.

Following this modification, the new memory chip (I used a Samsung KM416V4104CSL-5 from Interweb (www.interwb.com (No "E" in interwb)) purchased for $35 + $9 shipping ) was installed, except that _pin 33_ was not soldered down. Actually, I tore the soldertab when I removed the original chip, but I intended not to solder that pin down anyway. ("Really, I meant to do that." :-)

Addendum:RAM prices are volatile. The (overclockable) 50nsec part has gone up from $35 to $39. The (regular speed) 60nsec part is still $35. Double check with the supplier to verify current pricing.

Addendum (2/21/01): Samsung has changed their part number for the KM416V4104CSL-5 to K4E641612C-50. Pinouts appear the same.

This is a photo contributed by another user of his mod which shows the area nicely.

As you can see by my photos, I also accidently tore one of the soldertabs on the little "double jumper", and needed to run a wire to the corresponding DRAM pin. Once done, though, all was well.

And after a few minutes, my data was loaded and I was ready to work.

Bonus benefit:
By using the -5 version of the DRAM, the Afterburner Hack cruises at 26MHz without difficulty. 28MHz works well, but makes the musical AlarmHack alarms too short. Obviously, your milage may vary, but I've been stable at 26MHz and use 28MHz for the slow applications. Quite a boost from the default 16MHz and faster than a stock Vx.

Conclusion
Total cost was $150 for the Palm, $80 for tools / parts / solder => $230, still a hundred less than a Vx for what I feel is a more rugged yet "friendly" machine. If you figure the cost of the time it took to do the work (about 2 hrs start to finish), the dollar savings is a wash. Still, for me I think the improved ruggedness will be worth it.

Addendum:I've heard from a number of people who have attempted this mod. Please, if you are not experienced in surface-mount soldering, do not attempt this. There are now multiple sites that will upgrade your Palm for you if you don't have the experience. $50 for labor is cheaper than $150 for a new Palm.

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October 30, 2000