While I had the laptop in pieces I noticed that the base 256mb Ram mounted under the keyboard was also a 172pin microdimm, just like the accessible one underneath. So I bought a couple of 512mb ram upgrades, took the machine apart again and replaced both my 256mb microdimms with the 512mb ones. I now have 1gb Ram in my XV841. Well actually 995mb is reported by Windows XP. Fitting was easier than the hard disk because the system board doesn't need to be unscrewed. Once the 2 plastic halves are split and a few of the connectors removed, you can lift up the top half of the case enough to swap the Dimm. The screen does have to be removed though.

The first few times I powered up I got a power light and nothing else, no lights or display - panic!! I removed the underside 512mb Dimm module and got the same, so I re-split the case and swapped the 512mb module for the one I had just removed from the underside upgrade slot. This time it came up OK with just the single 512mb installed in the base slot. I put the 2nd Dimm in the expansion slot and the machine booted OK with 1GB, I guess I just hadn't seated the first Dimm correctly.

I didn't get any strange test or start-up processes, but the first 2 or 3 times the machine booted successfully, the start up splash screen had a "Victor" logo instead of the "JVC" splash. Now the machine shows the JVC splash like it used to.

The 80gb / 5400rpm disk certainly sped the machine up considerably, I'm not sure that the RAM has made any difference, but I haven't tried anything intensive with it yet. My first impressions were that it was slower, but that's probably due to my expectations and taking more interest in usual of the boot up process, and as I only completed the upgrade about 10 minutes ago I will need a bit longer to really get a feel for the performance :)

For info, I used generic 512 MB - MicroDIMM 172-pin - DDR - 333 MHz / PC2700 modules. Mine are badged Kingston and listed as Panasonic compatible. Buying Sony or other Laptop manufacturer labelled Ram will cost a small fortune, but the Kingston ones cost 44 UK Pounds ( 80-90 USD ) *each* delivered from Amazon.co.uk.

>To google for these Dimms:

512MB 172pin PC2700 DDR333 microDIMM

Kingston KTP-BAU/512, Kingston U6464C250, and Hitachi

Memory10 MDIM133-512M

Panasonic CF-BAU0512U

Sony VGP-MM552I (or L maybe)

Hitachi PC-MK7518

MemoryTen list KTP-BAU/512 and U6464C250 as the same module.

http://www.memoryx.net/cfbau0512u.html

I just noticed that this 1gb MicroDimm is listed as compatible with the XV841, that would mean that the XV841 might go to 2gb - but at nearly $600...

http://www.memoryx.net/jvcxdu1024.html

Thanks again

Tim