Hello,

My first post 😀

I used to work at a company called Sentinel located in Belgium in a small town called Wellen. They were a manufacturing company producing and duplicating 3,5" floppies when I joined the company. Later they were if I recall correctly the only manufacturer of the Iomega ZIP disks (100Mb and 250Mb) worldwide. Afterwards they went into the CD and DVD business. Again manufacturing and duplication of all sorts. Eventually they went bankrupt, partly of the USB devices and storage popping up.

I used to work there as an all-round IT guy fixing everything in a pre-Internet era. I still remember the IT manager at that time as being one of the best 'bosses' I ever had. Recently I came into contact with him via email and we exchanged some mails before I mentioned being interested in old MS-DOS kind of hardware. (I'm currently 46 years old). He then told me he had something that might interest me. I went on-site and he showed me a boxed Compaq SLT/386. I like to share my attempt at restoring this machine to its prior glory.

The laptop only booted from floppy disk. There was no hard disk activity. Also the BIOS settings were lost and didn't survive any reboot. The keyboard cable was in very bad shape and crumbled into tiny pieces. Time to fix this beauty 😀

First I disassembled the laptop to look for the hard disk. There is a nice YouTube video from EkriirkE that shows the whole process. https://www.youtube.com/watch?v=nVkarBW37hg.

When I opened the case I saw my old boss made some notes about the hard disk on the metal inside the laptop.

• Conner CFS210A
  685 Cylinders
  16 Heads
  38 Sectors
  210 Mbyte

This corresponded with the hard drive I found internally. I tried the disk on another computer. It spinned but didn't make any particular sound. So I tried to open it and gave the read-and-write head a small push in the hope that they would start moving again. Nothing happened and as I put more force on it they kept stuck. I then screwed up the disk attempting to further unscrew stuff on the heads... Long story short: dead disk beyond repair for me:-).

Next I ordered an SD-to-IDE adapter (SD35VC0) as a replacement. Since it's just a PCB without any casing I had to 3D print a small box so that the PCB wouldn't touch any internal metal components. I recovered the custom power connector (3 pins: 5V, 12V, Ground) from the old disk and soldered it to a piece of floppy power connector cable I cut from a PSU. Only the 5v and Ground pin is used on the PCB.

Next up to the bios. You need to use a floppy to run a tool to show/access any bios settings. (Compaq Setup Utility version 8.00 DP256). You can only choose from a list of predefined hard disk options. I just picked the largest one being option 51 (212.6 Mbytes). However when I closed the configuration tool and rebooted, the settings were lost. Apparently the CMOS battery was empty and wasn't able to store the settings. So up to checking the CMOS battery.

The battery is a Dallas DS1287. You can find lots of videos on YouTube how to repair this. I took me about 2 hours to carefully drill the necessary holes to reveal the battery pins. You need to cut them and rewire them to a new battery. I 3D printed a small case to hold the battery. Since the laptop battery was missing, I had plenty of room to put this case inside.

Next back to the bios, I enabled my hard disk, partitioned it, formatted it and was able to install MS-DOS. After rebooting, the system would just hang with a blinking cursor. It took me a few days and ultimately I did a fdisk /mbr and it solved my issue. I expected to get some kind of message that would indicate there wasn't a master boot record, but no. Anyway, problem solved. I was able to boot!

Last thing to fix: The keyboard. I opened it and these are some pictures that show the state. 31 years of dust nicely collected inside. I even found a staple inside. First I thought it was part of the keyboard 😀

I cleaned everything using cotton buds.

I washed the membrane with some clean water and dried it.

Last thing to repair was the PS/2 cable. Since the rubber was crumbling I ordered a PS/2 extension cable. Cut it in half. Soldered it to the original connector and re-attached it.

The end result, a brand new cable in the correct colour.

I'm happy to be able to restore the machine! Now game time:

Andy.