IBM 7561 Common Devices

Power Supply

7561 Overview

Content by Alfred Arnold (original HERE). Edited by Major Tom.

7561 Overview

Photo of IBM 7561 (Front)

The IBM 7561 belongs to a side-development of IBM's Personal Computer Division that builds PCs for industrial use. In such environments, it is not so important how cool a computer looks, but instead how good it can withstand the environmental conditions. This leads to a solid full-metal case that fits into 19-inch racks, extra cooling fans and a generally more rugged construction.

The 7561 is a derivative of the Japanese PS/55 Model 5550-T. It uses the same planar with four Micro Channel slots, a DBA-ESDI hard disk interface and the same power supply. However it has a completely different housing with a large (and noisy...) fan at the front. The fan has a dust filter for use in 'dirty' environments.

Photo of IBM 7561 (Cover off)

It almost looks like the designers of the 7561 took the innards of a PS/55 Model 5550 and built a new metal case around it. The internal construction is exactly like the aforementioned machine, including the snap-in mountings for hard drive and floppies.

Photo of IBM 7561 (Planar)

Note the seemingly unused space left to the planar. Louis' first thought was that it is the place of the optional battery pack, but it turned out that the battery pack is located in supply: that:

The 7561 had a 180W PSU, autoranging option.

I was wrong then, but I put out the correct answer- the backup battery fits inside the PSU itself. The screw that opens up it's compartment is at the front of the PSU on the outside. The plug is a three pin Molex.

So you could have a built-in UPS for this machine - very nice in an industrial environment...

Content created and/or collected by:
Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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