HP 9845B/C CE Service Manual

A-22 HP 9895A Disc Memory Command Set
Control Commands
Universal or Selected Device Clear
Type:
Purpose:
Description:
HP-IB
Sequence:
ATN
Control.
A clear places the
9895A in a known state. Thus, it is useful
when initializing a system on power up or after a host sys-
tem crash. The clear also allows a power up DSJ of 2 to be
cleared by sending a single byte. Since a clear updates the
device's HP-IB address, it is useful if the system is being
re-configured.
Upon reception of either a universal or selected device
Clear
command, the 9895A stops handshaking with the
HP-IB, parallel poll
response is disabled and the following
are performed:
1. The PHI is reset,
2. HP-IB is
updated from the device address on the
controller
board,
3. Stat 1 is cleared,
4.
Stat 2 is updated appropriately,
5. DSJ set to
0,
6. All drives are re-calibrated to physical track 0,
7. The target address is set to cylinder 0, head 0, sec-
tor
0/1 for HP /IBM format,
8. Disable HP-IB parity checking.
Universal Device Clear
ATN
P P
I POOI0IOO P P
Universal IDE
Selected Device Clear
ATN
P P
IPOI~DDRSI
Pnmary
I
POOOOIOO I ~ ~
Selected
Device

HP 9845B/C CE Specifications

General

Brand	HP
Model	9845B/C CE
Category	Storage
Language	English