HP 110 - Known Screen Problems ?

[Martin Hepperle]

Dear HP Portable and Portable Plus experts,

can these machines develop the same "screen rot" problems as the HP 100/200LX machines when stored in humid places? Is this a known issue (without a remedy)?
I guess that replacement LCD screens are not available for these machines.

Thank you,
Martin

[Dave Frederickson]

A Portable 110 sold on eBay recently for $20 which would provide a replacement screen and I have an enhanced display screen for the Plus that I'd be willing to part with.

Dave

[Martin Hepperle]

(11-12-2014 02:25 AM)Dave Frederickson Wrote:  A Portable 110 sold on eBay recently for $20 which would provide a replacement screen and I have an enhanced display screen for the Plus that I'd be willing to part with.

Dave

Dave,

thank you for the offer. I have discovered that the screen was not damaged - there was only a lot of dirt behind the glass pane in front of the LCD screen. Following the Service Manual for the Portable Plus I was able to remove and clean the glass and now the display looks fine.
Now I only have to get rid of a RAM error on this machine...or find a replacement CPU board.

Martin

[Jim Horn]

If you're adept with soldering and can find the old parts, the '110 has been modified in the past to give it 512k of RAM instead of the standard 272k. The extra RAM is useable as a fixed sized RAM disk in addition to the standard resizable RAM disk. The result is you can partition the 272k as RAM and the added 240k as RAM disk.

I no longer have the instructions on that as my '110 and all documentation was given away a few years back. If there is interest, I could ask the recipient to scan the instructions for the modification as well as the small program that creates the RAM disk.

Of course, the chips available have changed radically since circa 1985 so anyone familiar with microprocessor electronics could readily add to the motherboard to create a massive RAM or flash disk with very little added electronics and code. Anyone care to dive into that? A '110 or Portable Plus with a micro-SD card would be a heck of a portable note taker, considering their 20 hour battery life, instant on and off, full size full travel real keyboards and such...

[Dave Frederickson]

Here's a trick: Google something like "110 memory upgrade site:hpmuseum.net" and the first hit tells me the Portable Paper article is in Volume 2, Number 6.

[Martin Hepperle]

(11-25-2014 05:35 PM)Dave Frederickson Wrote:  Here's a trick: Google something like "110 memory upgrade site:hpmuseum.net" and the first hit tells me the Portable Paper article is in Volume 2, Number 6.

Dave,

thank you, that's an interesting article - and the author mentions that he used the Service Manual - unfortunately his email is nonexistent anymore.
The (de)soldering work makes me shudder a bit - it is a somewhat risky job and surely requires the right equipment. Now, if one could come up with a device driver and an interface for an a CF card for a RAM disk... I just saw 128 MB IDE-Flash modules for 2 € - just dreaming...
There should also be a simpler way to upgrade the memory drawer of the Plus - the 4MB extension cards mentioned in the Portable Paper indicate that.

Martin