Strange Jornada 728 unit (32 MB only). Adding RAM

Hi. This is my first post, I hope placed it in good subforum.
Sorry for my poor english. Hope that you understand me. If not, please ask.
Let's start:
I've bought some strange Jornada 728. It has probably daughterboard from 720 one (but system is from 728 - has VPN).

There are two Samsung k4s281632B chips on this board, that are 128Mbit each.
After a short search I've found This topic and this project.
Question is - does anybody have Jornada 728 64mb, not that crappy 32MB budget-european model? I'd be verry happy if one can unscrew her/his jornada's keyboard, remove the memory daughterboard and take GOOD macro photos of it, including chips' numbers and PCB details around chips.
I found owners of such cut 728's and want to get some way to add RAM to 32MB jornada 7xx. Chips used in flashboards have 2 pins more than k4s281632B and will not fit this PCB.

Back in the days when DOS was still quite popular I had HP 200lx and could add chips from damaged notebook's RAM module. And it worked. But 200lx (Intel Hornet chip) had additional ~CS sigal for second bank.

Studying address lines of Jornada 7xx memory connector i've realized that it' could be easy to add 2 256Mbit chips of the same pinout as k4s281632B, but I don't know what chips to use and need even photo of 64MB PCB to get idea about 32 MB pcb rework.

This week I will receive 2 pieces of 32MB daughterboards from Jornada 720 to start fighting with it. I hope that it's identical with my daughterboard.

I have needed tools, experience (and enough mana) to start this work, but need some info.

Would one help me - eg. co-work discussing this topic?

Igor

Edited by c64club 2009-07-22 9:54 AM

I don't understand - how come it has a 720 daughterboard but it has VPN? the ROM and RAM are on the same board... so if the device has a silver casing (like jornada 728) but has 32MB RAM, it is not possible for it to have VPN after fresh hard reset (you can install VPN dlls but those get lost on a cold boot).
please tell me more info... can you please take a photo of your daughterboard and post it? can you take screenshot of the VPN (if it is greyed out, it is a plain 720 ROM!!!)?

I don't have any photos of my 728 daughterboards, as none of them are in a disassembled state right now.

Edited by cmonex 2009-07-22 11:41 PM

Thanks for reply, cmonex. I don't know if it's 720 daughterboard. My Jornada is never disassembled unit (original "Void" stickers were on screws). It's grey/blue/silver color and has number 728. I think that it can be some budget-version made for Europe. It has UK keyboard and german system. And has ability to connect to vpn (didn't try it yet cause of lack of vpn in my company). Board could be the same as for 720 but with soldered half ddensity chips.
There are some numbers on daughterboard:
-CHR3ABD1 (means that it's D - deustch - german)
-5200960
-F1816-80060
-E119697
and the top layer is white-coated. typical 3com's style pcb. I've seen some low-q photos of these daughterboards from 728s and from 720s. Any of them were white.

If 256 Mbit chips have the same pinout as 128Mbit, then it's possible to use PCB with the same layout. It's common practice with RAM boards for PC
In "flashboard" project there are 512Mbit chips and they have 2 pins more than 128Mbit ones. But 256Mbit chips can come in the same package as 128 Mb. But I dont know what chips they soulld be. Think that some Samsung chips from the same family.

And that's the info I need. I know that WinCE will not recognize more memory tan 32 MB (even if it will be workable) but Linux should see whole space, cause its kernel believes the user - user must provide mem=xxxm parameter to kernel.

Now I havent jornada in hand, so the screenshot and some photos will be posted later.



Edited by c64club 2009-07-23 7:39 AM

Oh, I forgot. VPN is installed after HR, so (I think :P) it's in ROM. I make HR's constantly because of using linux.

And I have contacted few dudes in Poland having the same problem. German (and UK) J728 units, "new" clored (grey/silver/blue with some metal plate on cover) but with 32 MB of RAM. Hence I want to develop method to expand the RAM.

Edited by c64club 2009-07-23 7:37 AM