ZiLOG System 8000 Hardware Reference Manual

HRM
Zilog
HRM
SB contains
status
bits:
NAME
BIT
MEANING
SB:EC
0
error correction attempted
SB:RT
retry attempted
SB:RZ
2
rezero required to clear
fault
OS contains status bits returned from the selected drive.
The bit assignments for DS:SKE and DS:SEL correspond to
ports 0-3, not drives 0-3. In order for the drives and ports
to correspond, drive 0 is plugged into port 0, drive 1 into
port 1, etc.
NAME
OS:RY
DS:OC
DS:SE
DS:FT
'OS: RO
DS:BZ
OS:XM
DS:SM
DS:SEL
DS:SKE
BIT
o
2
3
4
5
6
7
8-11
12-15
MEANING
selected drive ready
selected drive on cylinder
selected drive seek error
selected drive fault
selected drive read only
selected drive busy (dual access)
index mark (internal use only)
sector mark (internal use only)
ports 0-3 selected
ports 0-3 seek end
CT is the number of bytes to be read or written in
read/write operations or the number of sectors to be read or
written in read/write format operations. If a CT byte count
is odd, the command is rejected. A NOP command returns the
microcode revision in CT.
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Zilog
4-39

ZiLOG System 8000 Specifications

General

Brand	ZiLOG
Model	System 8000
Category	Desktop
Language	English