ZiLOG System 8000 Hardware Reference Manual

HRM
SIGNAL NAME
Zilog
FUNCTION
HRM
Unit Acknowl-
edge 0 to 3
UNITACKO\ to
UNITACK3\
READ ENABLE\
WRITE ENABLE\
MASTER RESET\
BI-DATA\
SYSTEM CLK\
WRITE CLK\
The selected drive places its binary address
on these lines.
The controller generates this signal to read
the selected drive at the current cylinder.
Before activating this signal the controller
must send a control word 2 and then wait until
the selected drive returns the CYACK signal.
The controller generates this signal to write
to the selected drive at the current cylinder.
If the heads are write-protected, a fault
results. The controller must send a control
word 2 and then wait until the selected
drive retunrs the CYACK signal.
A high-to-low transistion on this line resets
all internal latches and output ports.
These lines form a bidirectional, differential
pair that transmits NRZI read data from the
currently selected drive to the controller
whenever READ ENABLE\ is active.
A pre-recorded pattern on the surface of one
of the disks on the drive generates this
signal. The selected drive sends this sigDal
to the controller: the controller derives
the write clock (WRITE CLK\) from system
CLLX. The controller sends the WRITE CLK\
to the selected drive.
This is a differential signal which the
controller derives from the SYSTEM CLK\.
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Zilog
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ZiLOG System 8000 Specifications

General

Brand	ZiLOG
Model	System 8000
Category	Desktop
Language	English