THE A-TOP AT900 MID-TOWER COMPUTER CASE
Last updated: 2/10/2000

BENT METAL.   The AT900 has a fairly solid feel and a good layout. All surfaces have a shiny, chrome-like finish.  The edges on the drive bays are rolled for strength and to reduce the possibility of cuts during assembly.   Other edges are thick and smooth to the touch.

The  case has two removable sides which slide into place (not quite as easily as the HX45) and have indents along the rear edge to aid in removable. The left side is secured by two knurled screws at the rear of the case.  The right side is fastened with phillips-head screws.  Although adequate, the sides would probably be a little better (and work better) if they were rolled at the top and bottom, had ventilation holes along the bottom, and had wider clips at the front.

The interior of the AT900 is divided into two compartments.  The first occupies the top 7 1/4" of the case and contains power supply and the 5 1/4" drive bays. The other compartment is clearly the motherboard compartment and it is wide open.  The only significant protrusion is the 3 /12" drive bay which is not removable.

The AT900 includes a pull-out drawer for the motherboard and expansion boards.  It is secured with spring clip along the bottom of the rear of the case and easily removed for motherboard, etc. installation.  This would make it very easy to assemble PC's in a production line.  When finally assembled the drawer should be further secured with additional screws along the left side of the back and in two places provided in the interior for greater chassis rigidity and grounding.  It would probably improve the ventilation of this case if there were vent holes above the expansion board slots at the back of the drawer.

The AT900 has an A.3.a I/O (Intel "Universal") back panel which cleverly clips onto the back of the drawer.  I gave it a slight whack with a screw driver to lock it into place.  The panel matches all of ATX motherboards reviewed in the Digest to date.  It is made of thick metal and is clearly labeled. (I erroneously took a picture of  the inside side of the panel and presently have no camera to retake it.)  Be careful, this is one of the few items that could cause a cut during installation.

There are two DB25 and one DB9 chassis knockouts on the back of the drawer and above the ATX I/O panel cutout to accommodate one printer and the two serial connectors which come mounted on brackets with Baby AT motherboard.  I would suggest one more knockout to mount the PS/2 mouse connector which ships with many quality Baby AT boards.

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