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Is it possible for a cable to be compatible with both SCSI and Serial?

MacFox

6502
I was just looking up SCSI cables on eBay and I notice that some of the listings say that the cable is for both SCSI and serial. Is it possible for a cable to work with both SCSI and Serial?

 
I'd be pretty careful using a serial cable for scsi.  SCSI cables usually had thicker gauge wires and more robust shielding and IIRC had pairs of wires twisted together to reduce interference, all of which is why an old school scsi cable is as thick as your finger vs serial cables which might be diameter of a pencil or less.  Serial cables were widely variable in quality.  Might work, especially for short distances, but be aware you may have errors creep in.  Gender changers should be ok.

 
Yup, I should have added that as a caveat: a cable that is good enough for SCSI will be good enough for serial, but the same is not necessarily true the other way around...

 
I'd be pretty careful using a serial cable for scsi.  SCSI cables usually had thicker gauge wires and more robust shielding and IIRC had pairs of wires twisted together to reduce interference, all of which is why an old school scsi cable is as thick as your finger vs serial cables which might be diameter of a pencil or less.  Serial cables were widely variable in quality.  Might work, especially for short distances, but be aware you may have errors creep in.  Gender changers should be ok.


Yup, I should have added that as a caveat: a cable that is good enough for SCSI will be good enough for serial, but the same is not necessarily true the other way around...
Good to know.

 
While on the subject of cables: an S-Video cable makes a great ADB cable, but an ADB cable makes an awful S-Video cable for the very much the same reasons.

 
I'd be surprised if serial cables work at all. SCSI is normally 50 wires with half being shield/ground. The DB-25 port used by Apple is not part of the SCSI standard and reduced pin count by combining all the ground pins at the plug end (the standard 25 to 50 pin cables have 50 wires internally). You won't see any SCSI devices normally using a DB-25 on the device end (the Zip drive is a notable exception), its usually a 50-pin Centronics style plug or the 50-pin Micro SCSI plug.

 
The reason why I’ve been looking at SCSI cables lately is that I am planning on buying a SCSI2SD v5.5.  I don’t want to plug it directly into my Macs because I still want to use my AppleCD 600e drive.  The connector on the back of the SCSI2SD is male 25-pin.  Based on the information from this thread I think I will use a serial gender changer to make the connector female along with a SCSI 50-pin centronics male to 25-pin male cable.  I saw a cable on eBay that is listed as a SCSI 50-pin male to 25-pin female cable, but it doesn’t say whether or not the 50-pin end is the centronics type.  I asked the seller, but haven’t gotten a response.

 
In the event that I’m not using the CD-ROM drive, I’ll use the gender changer plus a male to male SCSI 25-pin cable instead of serial.

 
I use serial 25 pin cables for connecting a SCSI2SD with compact macs (25pin to 25pin). The cables are straight through and I did not have any problems with that configuration. Works for all macs from plus to SE/30.

It also works with a 50 to 25 pin adapter or a gender changer (25 pin).

https://store.inertialcomputing.com/product-p/idc50f-db25f.htm

There are serial cables available with male - male 25 pin. Then you do not need a gender changer.

https://www.reichelt.de/d-sub-kabel-1-1-25-pol-stecker-stecker-1-8m-ak-401-p3996.html?&trstct=pol_0&nbc=1

(german seller)

 
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