Figure 2-11. Seek Instruction Format - Honeywell 6000 Series Reference Manual

rnSTRUCTION SET
The instruction set used with the DSS190 and DSS190B subsystem is shown in Table 2-3.
The instruction codes are sent by the EUS to the DSC on the interfaceli nes. Instructions
special to the DSC are shown in Table 2-4. The special
nsc
instructions cannot be mixed with
the normal instructions in the same channel program.
Instructions
SEEK
This instruction acquires the addressed disk pack cylinder for the logical channel issuing
the instruction.
The Seek instruction format is five bytes (shown in Figure 2 -11).
Sector Count Limit, Bits 0-11
These bits define the binary sector count. Bit position 11 is the least
significant bit 2°. All zeros is a maximum count of 4096.
Track Indicator (TI), Bits 12-13
These bits indicate a complete track as good, defective, or alternate.
00
=
Primary Track - Good
01
=
Alternate Track - Good
10 = Defective Track - Alternate Track Assigned
11
=
Defective Track - No Alternate Track Assigned
Sector Address, Bits 16-35
These bits define the specific binary sector address to be located on the
addressed DSU. Bit position 35 is the least significant bit 2°.
o
SECTOR
COUNT LIMIT
I
BYTE 0
TRACK
INDICATOR
I
BYTE 1
SECTOR ADDRESS
31 32
BYTE 2 BYTE 3
BYTE 4
Figure 2-11. Seek Instruction Format
2-11 DB37