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If you ever thought that your Model 95's case is far too small for your needs, the PS Server 500 might be the right machine for you. The photo above shows a comparison of the Server 500 with a Model 95.
Since the Server 500's case can become *really* heavy, there is a handle on top of the front to help lifting the machine. There are wheels on the back of the stand, so you easily can move the case once you lifted it a bit - unless it is standing on a carpet like here...
The front door that covers the drives for removeable media can be locked with the same key that also prevents removing the front cover. Note the 'drive cage' on the left: it is a storage compartment for the ServerGuide CD-ROMs, but removing it and placing an additional drive is also possible.
The foot's special shape assurest that when multiple machines are placed next-to-next, the minimum distance between two machines necessary for airflow remains. Makes it just a bit difficult to remove a machine located between two other ones 8-)
Similar to the PS/2 models, the case can be opened without any tools. The whole machine is optimized towards drive arrays (though most machines were sold without a RAID controller...). Altogether 18 drives may be placed in the case, organized in three groups with a common SCSI backplane. Additional electronics on each frames allows hot-swapping, i.e. drives may be added or pulled while the power is on.
Depending on how many SCSI drives are placed in the upper bays, not all bays in the topmost row may be used since they share the same SCSI bus. In this example, the CD-ROM uses up on ID, so one slot must stay empty.
The drives in this machine are IBM OEM versions of Quantum Atlas drives, and all drives have wide SCSI connectors. In fact, it would need a lot of tweaking to get narrow SCSI devices into the bays...
The planar in the machine is exactly the same as in the later Model 95, versions, i.e. the Type 4-based 9595-xxx models. Due to the different mechanics, the power supply connects via a long cable to the planar and there is no 'snap in' system. The supply delivers 434 watts. As soon as the 3rd group of drive bays is used, it is necessary to add a second 200W supply. The new supply gets switched on and off by the primary one.
Together with the Server 500, a new CPU complex based on a Pentium-90 was introduced (if your Model 95 has a P90 complex, it was upgraded). The important thing that makes this complex a highly desirable board is the fact that the socket allows upgrading to faster CPUs - there is no working upgrade for a P60 or P66 complex...