[comp.sys.sun] SCSI cable length

tek@uunet.uu.net (Ted Kim (ATW)) (12/12/88)

erickson@ics.uci.edu (Gary Scott Erickson) writes:
>I would like to attach a shoebox disk to the SCSI port of a 3/60.  Anyone
>know what the maximum length can be?  The person using the 3/60 would like
>the disk in a different room because of the noise.

The recommended maximum is 6 meters. With the cable in the box and the
various connectors, we cut our cable to be 18 feet.

The length figure comes from what we read in the back of the Adaptec 4000
(SCSI controller) manual. It is supposed to be based on the following: 

True (LOW signal) = 0 to 0.4 VDC @ 48 mA (max)
False (HI signal) = 2 to 5.25 VDC 

open collector drivers terminated with 220 ohms to +5 V (nominal)
	and 330 ohms to ground at each end

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karl@spruce.gsfc.nasa.gov (karl anderson) (12/16/88)

> I would like to attach a shoebox disk to the SCSI port of a 3/60.  Anyone
> know what the maximum length can be?

I'm using a 40' SCSI cable for a SunIPC board floppy drive.  The board is
in a machine across the hall, while the drive is on my desk.  The cable is
attached to the "SCSI" port on the board, and runs across the hall through
the ceiling.

Karl Anderson
NASA/GSFC code 623 (STX)
(301) 286-3815
ARPA: karl@spruce.gsfc.nasa.gov