Custom SCSI Ribbon Cable
- 50-position and 68-position internal ribbon constructions
- Flat ribbon and paired/twist-and-flat options by equipment requirement
- Male, female and mixed connector arrangements
- Two-connector or multi-drop harness layouts
- Drawing-controlled connector order, spacing and orientation
- Pin-1 stripe, keying and strain-relief definition
- Optional terminator only when the system design requires it
- Electrical and visual inspection to the approved harness drawing
Custom SCSI Ribbon Cable Assemblies
An internal SCSI ribbon cable looks simple until it must fit a real chassis. Connector spacing, pin-1 direction, key position, and the order of multiple drops can matter just as much as the conductor count. A few millimeters or one reversed connector may prevent installation even when every continuity reading appears correct.
We build custom 50- and 68-position ribbon assemblies from a clear harness layout. Send the board and drive interfaces, connector centerlines, overall route, desired cable style, and any terminator requirements. If you are replacing an existing harness, a flat overhead photograph beside a ruler is especially helpful. For a broader comparison of internal and external formats, visit our SCSI cable collection.
Specifications
| Item | Available Configuration |
| Position count | 50 or 68 |
| Cable style | Flat ribbon or application-approved paired/twist-and-flat construction |
| Connector arrangement | Male-to-male, male-to-female, female-to-female, or multi-drop |
| Connector quantity | Two or more, subject to topology approval |
| Spacing | Each connector centerline stated on the drawing |
| Orientation | Pin-1 stripe, key, polarization, and cable-fold direction documented |
| Termination | None, integral or separate terminator when specified by the system design |
| Strain relief | Connector and route dependent |
| Marking | Pin-1, device position, customer P/N and branch labels available |
| Inspection | Continuity, shorts, orientation, dimensions, and visual workmanship |
Models and Configuration Options
These codes identify starting families. The finished part still requires the connector type, number of drops, spacing, orientation, length, and termination details.
Measure Connector Centerlines, Not Just Total Length
For a multi-drop harness, the useful dimensions are the connector positions along the cable. State a common datum and give every centerline measurement. This avoids accumulated errors and makes inspection straightforward.
Show Pin 1 on Every Connector
Do not assume all IDC connectors face the same way. Mark the stripe, key slot, and mating direction for every position. If the cable folds inside the chassis, show the fold direction separately from the connector orientation.
Termination Belongs to the System Plan
A terminator should not be added because another harness has one. Identify where the cable sits in the bus, whether the device provides termination, and what the equipment manual requires. We will build the approved arrangement, not guess the topology.
Information to Include With Your Ribbon Cable Drawing
List the 50- or 68-position connector type, the number of drops, each connector centerline, pin-1 orientation, keying, and the overall cable route. Identify the host and every device position. If the harness includes a terminator, show its exact location and part requirement. Include the quantity, customer part number, and any individual packaging or service label.
If your project uses an external half-pitch connector instead of an internal header, compare the mechanical choices on the 68 Pin SCSI Cable page before finalizing the drawing.
They use different conductor counts and connector systems. Selection must follow the equipment interface, not the available chassis space.
Yes, when the connector order, spacing, topology, and termination are approved.
Use a stated datum and measure to each connector centerline. Include a sketch showing the measurement view.
Yes, if the drawing clearly shows its orientation and the wiring is valid for the equipment.
No. Termination is added only when specified by the system design and approved order information.
Yes. Please supply a known-good sample or photographs showing the flat dimensions and installed fold directions.
Yes. We can identify the host, drives, connector sequence, and customer part number.
Yes, when each harness has its own part number, and the packaging list clearly states the quantity and installation position.
Reference the approved part number and drawing revision. If the chassis has changed, review spacing and orientation before reordering.
Yes, subject to availability and production suitability. Tell us whether alternative parts require written approval.
What a Production-Ready SCSI Ribbon Harness Drawing Should Show
A clear drawing removes uncertainty from quotation, assembly, inspection, and field replacement. It does not need elaborate CAD, but it must answer the questions that affect fit and wiring.
Begin With a Fixed Datum
Choose the cable end or first connector centerline as zero. Dimension every other connector from that point. Avoid a chain of small dimensions, because one variation can shift all later positions.
Name Each Connector by Function
Labels such as HOST, DRIVE 1 and DRIVE 2 are more useful than J1, J2 and J3 when technicians work inside the machine. If the harness is directional, repeat those labels on the finished cable.
Mark Orientation in More Than One Way
Show pin 1, the colored stripe, connector key, and mating side. A photograph or simple end-view sketch can clarify what text alone leaves ambiguous. For female connectors, specify the drawing view so numbering is not mirrored.
Include the Chassis Route
Note folds, clearances, sharp edges, and strain points. Ribbon cable should not be pulled tight across a metal corner or forced into a fold directly at the termination. When space is limited, an annotated chassis photo helps us understand the intended route.
Define Inspection Dimensions
State tolerances only where the assembly needs them. Connector locations near fixed drive bays may need tighter control than a free tail at the end. A practical drawing balances fit with manufacturability.
When you send an old harness, lay it flat without stretching it, include a ruler, and photograph both sides. Tell us whether it is a working reference and which connector serves each device. That context turns a ribbon of plastic and copper into a repeatable part your team can order with confidence.
Approve the Harness in the Real Chassis
Bench continuity doesn’t prove a harness fits. During first-article review, install it in the intended chassis and check connector reach, fold direction, strain relief, airflow, and access to nearby components. Confirm that the pin-1 stripe remains visible enough for service work.
Preserve the Approved Geometry
Record connector centerlines and orientation in the controlled drawing, then assign a unique part number to every layout. Two harnesses with the same connector count but different spacing should never depend on a handwritten bag note. For repeat production, the drawing revision becomes the reference for manufacturing and incoming inspection.
Match Quality Records to the Risk
Most orders require dimensional and electrical checks against the drawing. Projects with more complex multi-drop arrangements may also request a first-article record or connector-position inspection. Review our quality control process and state the required evidence during quotation.
Package the Harness Without Losing Its Shape or Identity
Define whether each harness is packed flat, gently folded, or coiled within an agreed space. Avoid packaging that puts a sharp crease next to an IDC termination. If several layouts ship together, label every bag with the part number, revision, and installation position. For line-side kits, the packing list should show exactly which harnesses belong to one machine.
Recheck the Drawing After a Chassis Revision
Moving a drive bay or controller board can make an approved harness too short or place a connector on the wrong side of a fold. Treat chassis revisions as a reason to review connector centerlines and orientation, even when the electrical design has not changed. A quick geometry check is less costly than modifying finished harnesses during assembly.
