SCSI adapters are internal or external pieces that convert from one connector type to another, allowing the use of cables and devices with different connectors. The descriptions of our adapters specify the type of connectors on the adapter itself. For example, a 68 pin male to 50 pin female adapter will be used to mate a 68 pin female and a 50 pin male connector. We gave grouped the adapters into three categories depending on whether the devices and cables you are working with are internal or external:
- Below are the pictures, widths and types of various SCSI connectors. If you find it difficult to identify the connector from the picture, simply measure the width of the connector from edge to edge (excluding any posts) which should match the number in the width column. You can also count the individual "pins" on the connectors which should be 25, 50, 68 or 80 as appropriate. The connectors shown here are the ones that would appear on the devices - cabling would have the opposite gender.
The connector type of is an indication of whether the connector applies to an internal or external device, as well as a narrow 8-bit or wide 16-bit device (please see #3 below.)
Name Width Connector type Centronics/CN 50 2.5" External Narrow DB25 1.5" External Narrow HD50/MiniDB50/HPDB50 1.38" External Narrow IDC50 2.6" Internal Narrow HD68/MiniD68/HPDB68 1.8" External Wide HD68/MiniD68/HPDB68 1.8" Internal Wide 0.8mm VHDCI 68/HPCN68 1.25" External Wide SCA 80/LVD SCA 2.15" Internal Wide Hotswap
- Our adapters work with either the older Single-ended (SE) or the newer low-voltage differential (LVD) devices. Please note that while you can attach a slower single-ended device to a SCSI bus shared with faster LVD devices (Ultra2, Ultra160 and Ultra320), all devices on the bus will run at the slower 40MB/sec SE transfer rate. No such concern exists when mixing LVD devices rated at various speeds - each device will run at its (and the controller's) maximum rated speed.
- All bits on the SCSI bus needs to be terminated, but when you are connecting a wide cable to a narrow device, the device cannot supply the termination for the upper 8 bits of the 16 bit wide signal path. Correct functionality can only be guaranteed by using an adapter with high-byte termination. Most, if not all, suitable adapters we sell have high-byte termination for this purpose.
- Certain standards exists concerning connector genders: Internal IDC 50 pin SCSI cables have female connectors and the IDC 50 pin drives have male connectors. These are drives rated UltraSCSI or slower. Internal HD 68 pin cables have male connectors and the HD 68 pin drives have female connectors. These are drives rated Ultra2, U160 or U320.
- External SCSI cables are simpler. The connectors on the cables are typically male and the device connectors will be female.
- There is no SCA cabling.
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