HP 1000 A400

The A-Series computers shared some basic form factors. All of these computers came in a standard 19-inch rack mount box that could accommodate 20 expansion cards. In 1983, HP introduced its “Micro” form factor. The MICRO/1000 was a 14-slot box that could be mounted vertically as a rolling pedestal or mounted horizontally in a standard 19-inch rack. All A-Series were available in the MICRO/1000 format. In 1987, HP introduced its Micro 14/16 form factor for the A400 and A600+. This 6-slot “Cooler” box could operate in warmer environments (up to 60 degrees C) and shared the same classic industrial design as the 300 Series computers. The A700 and A900 were not made available in the "Cooler" form factor.