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Sorry, it isn't organized so well, I am slowly trying to compile information for the AST Powerexec. By most people's standard, this machine is obsolete. I consider it to be right at the borderline of usability, especially for my purposes. I like to use out of date hardware because it can be aquired so cheaply, and if you know how to use it, can still make very good computers! The AST Powerexec is nice because it is very easy to take apart and re-assemble and since there were so many of them made, they are easy to get ahold of. Here are some interesting facts about the machine:

• There were 3 processor types used with the PowerExec, a 386sx/25 model, a 486SLC/25, and a 486SLC33. Motherboards are interchangable, but RAM may not be. RAM voltage is different on different CPUs.
• There were 3 screens made for it: The black & white, color (single-scan passive matrix) and colorplus (Active Matrix). All screens are 640x480 resolution and can do 256 colors (or grayscales), except for the EL model, which only has 256K of video RAM on the motherboard, hence can only do 16 colors in Windows, but DOS applications can still use the low-res VGA modes with 256 colors. All 3 screens will work on any powerexec simply by changing the screen. The screens are super-easy to change too. FYI: the passive-color screen has to be the worst passive-color screen I've ever seen on a laptop. The contrast sucks and the shadowing effects are the worste I've seen. I just about prefer the black&white screen instead. The active-matrix screen, on the other hand, is beautiful!
• The memory came in two styles, 3V and 5V. I'm not sure how to tell which unit takes what kind. The socket is backwards on different ones to keep you from inserting the wrong kind. Depending on which type of memory your system takes, it is the same memory used in the AST Ascentia 900n and 910n laptops. This is significant because memory is hard to find for the PowerExec!
• Powerexecs have a good service-history. I used to work for the AST Laptop support line. About the only "common" problem they have is the keyboard. Some of the keys eventually get sticky. I've been trying to figure out the cause and a way to repair it but so far I just replace the keyboard with a better one.
• Power Adapters and batteries, and harddrive caddies are also exchangable with the Ascentia 900n and 910n systems.
• The unit was also marketed as a Grid 4025 (in black), under the name of Unisys (not sure of model# yet), and as a Digital DECpc 425SLC. Most of the parts should be interchangable. I came across a harddrive caddy which fits the PowerExec but had IBM on it, with that black plastic you usually see on IBM thinkpads for the front cover. No idea which IBM it came from, but it fits the Powerexec (and 900n/910n too, I guess)
• Maximum RAM is 32 MB, but is hard to find. BIOS has a harddrive limitation of 504MB since it does not support LBA. This is no problem if you are running Linux, like I am, but Windows users will need a BIOS overlay program.
• Graphics chip is Western Digital 90C24 which is well supported under Windows and Linux/XFree86. Maximum screen resolution is 800x600 on external monitor. Maximum colors is 256. Note: Some PowerExecs (I think the EL model) only came with 256K video RAM, so you will only get 16 colors when running at 640x480. Otherwise your unit should have 512K.
• PCMCIA controller is a genuin Intel I82365 (not just a "compatible") so all operating sytems work well with it.
• The unit had an option for an external trackball which attaches to the front and connects in that "weird" rectangle area next to the harddrive caddy and under the insert/delete keys. However, I choose not to use it since it also has the "soft-mouse" which can be used by holding down the FN key and pressing on the cursor keys to move the mouse. Your left and right mouse button are activated by the Z & X keys (while holding down FN) Since I usually use Linux on the machine and tend to use the keyboard for most everything, the occasional need for a mouse is well suited by the soft-mouse setup. I love it. I do have a trackball, but never use it. If I am using it on a desk, I plug an external PS/2 mouse into it!
• If you are using Linux, try some of my suggestions on using linux with low-memory to speed things up a bit!

This is surprisingly simple. You don't even have to take the computer apart. Just remove the memory cover (in the center of the computer, right above the keyboard) by pressing down and pulling back. Take the memory modules out.. Be carefull not to damage anything. You may need a flat-tip or something to carefully pry them up. Once out, you'll see the cable that connects the screen to the motherboard. Just take out the 2 screws that go "through" the ribbon cable, then undo the ZIF sockets. Now, pry the two hinge-covers off using a flat tip screw-driver and some patience. Underneath you'll find two screws on each side which hold the screen on. Take them off, and voila! You have removed the screen!

First, turn the unit upside down and remove the 4 screws which hold the keyboard in place. They are on the bottom, at the front edge of the laptop. Once these are out, the keyboard lifts up. You can remove the ribbon cables via the ZIF connectors. If you wish to remove the top plastic piece, beware of two quasi-hidden screws. They are at the very back, on the bottom of the unit, right next to each of the adjustable rear feet.

If for some reason you want to take the screen apart, there are two strips of sticky plastic towards the bottom of the screen that are about 1/4" tall and 2" long. Remove these and you'll find the screws underneath. Be carefull not to bend these too much or they may never go back on properly. I believe when AST serviced the machines they replaced this part each time. But if you are carefull you can save them.

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