IBM SCSI-2 F/W Chipset

SCSI Controller "Cutlass"
MCA Interface Chip "Malibu"

SCSI Controller "Cutlass"

The Cutlass controller is used on all F/W SCSI variants:

I guess that the 52G9307 chip was first, some issues with it, it was then replaced by the (relatively rare?) 61G2444 chip. Production then stayed with the 82G2645 until end of production. Only one Differential Fast/Wide SCSI controller chip has been seen and that is the 52G9707.

52G9307SEPossible flaw? Not critical, affects certain scanners.
61G2444SEAssumed fully functional
82G2645SEAssumed fully functional
52G9707DiffAssumed fully functional

MCA Interface Chip "Malibu"

All F/W SCSI variants use the Malibu 61G2323 MCA interface chip.

Possible MCA Interface Chip Problems (RS/6000 Specific, but may affect PS/2s?)

Some MCA bus interface chips, P/N 61G2323 (Malibu), can cause system problems. The third line is the datecode. The following datecodes are suspect:


The entire datecode is not bad, but because of this, the whole lot is suspect. If you have any of the symptoms below, keep in mind the SCSI-2 F/W adapter may be the problem.

There are three types of symptoms you may see:

  1. Checkstops (SIO BUS 0 or 1 PARITY)
  2. System Hang/Unresponsive
  3. DMA_ERR in the Error Log

Affected Controllers

SCSI-2 F/W Controller TypeFRU P/NU-location
Integrated *52G4325U60
MicroChannel SE11H3600U5
MicroChannel DE11H7660U13
Enhanced Microchannel DE52G3380U16

* The Integrated SCSI-2 F/W controller is the one on the I/O planar of the 7012-380/390/39H and 7012-3AT/3BT/3CT systems.

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