ZiLOG System 8000 Hardware Reference Manual

HRM
Zilog
HRM
FAULT - When true, a fault condition exists in the SMD. The
following types of faults are detected: DC Voltage, Head
Select, Write, Write or Read while Off Cylinder, and Write
Gate during a Read operation. The line may be cleared by
Control Select or Fault Clear with the CONTAG enable.
SKERR - When this line is true, a Seek Error has occurred.
This line indicates the unit was unable to complete a move
within 500 ms or that the carriage has moved to a position
outside the recording field or received an illegal track
address. A Return to Zero (RTZ) clears the Seek Error and
returns the heads to cylinder zero while enabling the ONCYL
signal to the controller.
ONCYL - The On Cylinder status indicates the servo has posi-
tioned the heads over a track. The status is cleared with
any seek instruction causing carriage movement or zero-track
seek.
INDEX - The signal occcurs once per revolution and its lead-
ing edge is considered the leading edge of sector zero.
Timing integrity is retained throughout seek operations for
all SMDs.
READY - When true, with the device selected, this line indi-
cates: the SMD is up to speed, the heads are positioned over
the recording tracks, and no fault condition exists within
the SMD.·
OPENCABLE - The open cable detector circuit disables the
interface when the SMD A interface cable is disconnected or
controller power is lost.
SELTAG - Using SEL1 through SEL8, the Unit Select Tag gates
the desired binary logic number of the unit selected into
the logic number compare circuit.
SEL1,SEL2,SEL4,SEL8 - These four lines are binary coded to
select the logical number of one of sixteen devices. The
individual unit number (0 - 15) is selectable by a logic
plug on the units operator panel.
SELECTED- (1.- 4.) - When the four (SEL1, SEL2,SEL4,SEL8)
select and compare the logical number with the selectable
individual unit and the SELTAG is received, the SELECTED-
line becomes true and transmitted to the controller on the
SMD B cable.
WPROT - Enabling the Write Protect function inhibits the
writer under all conditions, illuminates an LED, and sends
the WPROT- signal to the SMDC A controller. The Write
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Zilog
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ZiLOG System 8000 Specifications

General

Brand	ZiLOG
Model	System 8000
Category	Desktop
Language	English