SCSI-1 included a single-ended (SE) transmission supported by a passive termination.
Passive termination is rarely used today because it was designed for low-speed and short distance SCSI-1 devices.
A: Passive termination is a resistor stack: Termpwr (4.0 to 5.25 Volts) 220 ohm resistor to the signal line and 330 ohms from the signal line to ground.
Bus errors and random bus hangs will occur with passive terminations with large configurations or high speed.
As SCSI bus speed increased, this passive termination
was not adequate.
Q: What is the difference between active and passive termination
on a SCSI bus?
A small K implies the potential for instability over a wider range of passive terminations
. Therefore, optimizing a termination for best output power will have more flexibility.