Compaq Portable II

Restoring a 1987 Compaq Portable II

Someone years ago gave me a Compaq Portable II. I always have loved this machine. Coming from the days of “luggable” computers, it weights over 20 lbs, and has a tiny CRT. The model I have has a “Type 2” (20MB) hard drive, and 640KB of RAM. For a little bit I thought my parents had accidentally thrown it away, as I was storing it at their house. Then it was found again and much rejoicing was had. The system is a Intel 286, with no math co processor.


Recently the one I have has come down with a few problems, so after seeing a brave young soul take their apart ( I decided I should give it a go. First the battery on the motherboard started to fail, not only resetting the clock when it lost power, but also forgetting the type of hard drive it had. This made it so every time the system was used, you would boot a 5 1/4″ floppy of MS-DOS, then change floppies to the Compaq Diagnostic disk, and configure the BIOS, and finally go back to the MS-DOS disk. I was lucky that some places still have the disc images online; . I attached those disks to the bottom of this page just so there is another mirror online for others.

I knew that the BIOS battery needed replacement, but when I recently turned the system on the old hard drive had finally given up. At about 30 years old I can not blame it. A fun fact about the drive in this system, it is actually a MiniScribe MFM hard drive (more info here that has a MFM->IDE conversion board on it. The drive is also shock mounted, this computer is portable after all! Knowing that, I decided it was time to swap that dead drive for a Compact Flash -> IDE adapter. This would be a size and speed improvement over this old hdd. Luckily someone else had already attempted this!

Armed with all that info (and the manual – I took the system apart, and very carefully avoided the high voltage CRT area. After getting the top cover off, then the front bezel; I needed to remove was the floppy and hdd caddy. I removed the cover of the caddy as well as the rear card cover. Then I could get access to the ISA cards. This system has the standard IDE control board, the video board, then a blank, and finally a board called EVEREX with a crazy connector. I have no idea what that last board ever went to. Some quick googling says it may be a tape controller card, or an special external monitor. My plan was to use the third slot to put the Compact Flash adapter, that way I can access it externally. (Here is it being tested)


I got a 8gb card off Amazon because it was fairly inexpensive and that would be so much more than plenty. After looking through all the options the system gave me, I settled on a “Type 41” hard drive even though the system auto detected it as a “Type 14” This gave me around 250MB of storage, for my uses that was plenty.

Now to replace the BIOS battery. The manual covered this. The battery is under the cover, where the extra RAM would be, IF I HAD IT. I took the bottom off, cut the zip tie that held the battery, and replaced it with one off Amazon. That first battery lasted about 25 years before it finally stopped remembering, I think that is a good battery.

One thing that stood out was the battery. I got a battery from the same company as the original, photo above; the battery on the left is the new one, the one on the right is the 30 year old battery. These batteries are 30 years apart, yet they look almost identical. I think that’s hilarious and interesting.

It came time to close up the case, mostly replacing metal covers around the system then placing the cover over it all. I ran into a little problem replacing the ISA card cover, there are little feet that hold the cards in place, but my IDE cable and power cable were in the way. I had to push the cables closer to the ends of the cards to make the cover fit. Then I used plastic twist ties to hold the power cable in place.

Right before sealing it up again, I cleaned the cases because it was already off. Below are some photos of the final system. The next thing I would need to do is replace the keyboard cable, the plastic is chipping off. I did a quick glance at how hard that repair would be, the issue is the cable goes into the monitor compartment (high voltage capacitors are scary) and I will need to solder a new cable to the keyboard/cable which is more than I was looking to do in this first repair session. I also one day should get a ISA RAM expansion card. A giant benefit to having the Compact Flash card slot on the side, is if I want to load more software I can just take the card out and plug it into a modern PC. I also can create a VM and use that card as the hard drive, making for easy dsk file image installation. This is close to infinite times faster than serial connections to transfer files.

This system has a Intel 286 with 640KB of RAM. To run Windows 3.1, you need extended memory; which I currently do not have. If I had a 386, then I could create a page file, and use disk space as memory, but a 286 does not have this ability. To have some version of Windows I installed Windows 3.00a off of, they have a great collection of Windows versions, with different languages and builds. I have a ton of old Windows versions in packaging, but this was simply easier. I also got a MS-DOS 6.22 bootable installation image off of and installed that as my base.

All in all, this PC got some much needed attention and is now back to its old self. The Compaq Portable II is back to its old brilliance with Windows 3.0 on its 250MB SDD (technically it is a SSD), 5 1/4″ drive, and tons of games, as it should be.

Random bonus: I enjoy the Compaq Setup Disk load screen, it has a animation with the logo that uses the slow refresh time for an interesting effect. Below is a Imgur upload of it.