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ZXnet http server: QBus Cards: CMD CQD-220/M/TM



DEC Systems

DEC hardware

CMD CQD-200/M/TM QBus SCSI Controller

The CMD CQD-220 is a QBus SCSI controller that supports the MSCP and TMSCP protocols and SCSI optical, magnetic disk and tape drives. Unlike the Emulex UC07/UC08 SCSI controllers, the CQD-220 doesnt seem to require any special configuration when adding new disks. I was able to just plug in the drive and use it - no need to go into firmware and write special formats. The manual lists three main variants: CQD-220/M (Disk only), CQD-220/T (tape only), and CQD-220/TM (Disk and Tape). The T means TMSCP and the M means MSCP. There are various other versions that support features like shadowing (/TMS), MicroVAX III enclosures (CQD-223), etc.



I have never had to reconfigure my two controllers (they were already configured in the machine they came with) so I have not looked into the configuration options. The user manual should have plenty of detail though.


Both of my CQD-220s just have a standard 50-pin narrow SCSI connector on the edge of the card - no funny pinouts or anything like that. I cant say anything about the MicroVAX III (CQD-223) versions.



CMD CQD-220/TM. Click on the images below for a larger version. There is two sets of photos with different lighting for this card.
[CQD-220/TM Front] [CQD-220/TM back] [CQD-220/TM Card Text] [CQD-220/TM Front (different lighting)] [CQD-220/TM Back (different lighting)] [CQD-220/TM Card Text (different lighting)]
CMD CQD-220/M:
[CQD-220/M front] [CQD-220/M front with cable] [CQD-220/M back]

In Collection

Qty: Systems: Model:
1 akvax CQD-220/M
1 akvax CQD-220/TM