STATUS REGISTER ENCODING
During the Result Phase of certain commands, the Data Register contains data bytes that give the status of the
command just executed.
Table 14 - Status Register 0
BIT NO.
SYMBOL
IC
NAME
DESCRIPTION
7,6
Interrupt Code 00 - Normal termination of command. The specified
command was properly executed and completed without
error.
01 - Abnormal termination of command. Command
execution was started, but was not successfully
completed.
10 - Invalid command. The requested command could
not be executed.
11 - Abnormal termination caused by Polling.
5
4
SE
EC
Seek End
The FDC completed a Seek, Relative Seek or
Recalibrate command (used during a Sense Interrupt
Command).
Equipment
Check
The TRK0 pin failed to become a "1" after:
1. 80 step pulses in the Recalibrate command.
2. The Relative Seek command caused the FDC to
step outward beyond Track 0.
3
2
Unused. This bit is always "0".
H
Head Address The current head address.
Drive Select The current selected drive.
1,0
DS1,0
34