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Thread: Upgrading memory on a Compaq Portable (and replacing the foam bits)

  1. #1
    Join Date
    Mar 2019
    Location
    Brighton, Colorado, USA
    Posts
    4

    Default Upgrading memory on a Compaq Portable (and replacing the foam bits)

    I just acquired a Compaq Portable in good condition, it boots up, reads disks and all that. But it only has the factory standard 128kb of memory. How would I go about upgrading the capacity to at least 256kb?

    Additionally, it has not been refurbished, and the foam pads in the keyboard are beginning to disintegrate. I've already lost the space bar. I just checked, and it seems that Texelec's replacement pads are sold out, for an indeterminate amount of time. What can I do to fix the keyboard? Are there other premade kits to replace them, or should I try to make my own?

    Any help is of course greatly appreciated.

  2. #2

    Default

    It should hold at least 256K on board. If it's got later versions of BIOS and the memory decoder PROM, it can get up to 640K on board. It should be just normal 4164 chips in both banks to get to 256K and 41256 chips in one bank to get to 640K. Here is a reproduction of the decoder: https://monotech.fwscart.com/Compaq_..._19805777.aspx and you'll still need to get BIOS version C or later (if you don't already have it).

  3. #3

    Default

    You can make your own replacement disks for the keys - I came close to doing that a couple of times, even collected the correct height foam with plastic backing already attached from an old printer, the mylar foil and a punch from harbor freight. In the end, I went with disks from texelec and once installed, they work great. They were definitely worth waiting for.

  4. #4
    Join Date
    Dec 2016
    Location
    South Carolina , United States
    Posts
    48

    Default

    Texelec has the foam pieces back in stock. They wrote me an email the other day saying that they are back in stock. For me it was too late. I made my own.
    https://texelec.com/product/foam-cap...ads-keytronic/

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