As another find at the retro computer day I picked up these two AST Premium Exec 386SX’s that both looked pretty interesting and being the same machine I figured if I could get one to work out of the two of them then I would be in luck. I was in the zone to try get old machines working again and give them that new lease on life so I figured i’d take on the challenge and it might even pay for some of my other purchases.
Condition
The condition of the units wasn’t overly great with one of them being in good condition and the other one having a cracked screen hinge. Both had battery corrosion and would not power on so some deeper issues lay ahead.
Power Up
Because the batteries were dead I had no immediate way to power them up and it turns out that these machines used a very strange power connector that nothing else used. But a quick bit of googling later and I found that the connector was sold at Jaycar and all the pins were actually just 5V and Ground so I wired them up and they sprang into life, kind of. One of them worked but one of them didn’t. There was a couple of capacitors that I had to replace to get it to power up.
Operating Systems
I was hoping I could load up some old DOS games on these machines but that dream was quickly dashed when I realised these had STN panels in them, something that was not great for much, especially games as they are really blurry. I did manage to get Wolfenstein 3D working on one, although extremely unplayable due to the screen. These machines are also only black and white.
I ended up loading DOS 7.1 on one of them via floppy and Windows 3.1 on the other.
Gut Shots
All the internal batteries were dead as well as the backup batteries and one of the harddisks, which I swapped with a IDE to CF adapter. These machines had a hard limit on the size of the HDD they would see so getting anything bigger than 2GB to show was not easy, but I got there in the end.
Nice job resurrecting these. I got the same machine and I’m trying to do the same thing. Unfortunately I don’t have the charger but found the plug so I can make a new one. Which pins you powered to get it on? Also, do you know the pinout of the battery and what voltage is supposed to deliver?
Sadly I don’t have them anymore. But you can find the pinout by probing the battery terminals which are labelled.