IBM System/370 145 Reference Summary page 65

L
_J
• Ten-Bit Positions For Each Byte
• Bytes are read serially, by bit
c
Start bit indicates
the be gm n mg of a
byte. This bit "
, , Clock Bits
; .
present for every byte.
- - ... 30us -
I I
I I
Start : :
c c c
D
I
0
0""-../1
I
c
I
1 ...
Data-Bit Value (O or 1)
....
......
........
D
c
..
,
I
3 6
BYTE FORMAT
r
P-b1t maintains odd
parity (excluding
start bit).
Data-Bit Pos1t1ons
[\
c
D
c
D
0
.-
.-
- -
.-
....
---
I
c
0
.-
Start bit indicates
the end of the current
byte and the beginning
of the next byte.
~
Next
c
D
c
I
I
I
.- J
c
Hexadecimal Value for
Example Shown.
Sector Format
• Maximum of 255 Bytes per Sector
0
,...
Track and
Sector
Address
-
Sector
pulse
Always a console-ftle
disk address (CFDA)
byte
Byte Number
Command
Always a command
byte.
One Byte
One Sector (83.3 ms)
~3
253 254
Vi_
Sector-End
Next Track
Data Data
Command
and Sector
Address
~~:
!t
-~
,.
Arrangement of byte types varies. The adapter recognizes byte types m this
area by their sequence.
3.5
its
r-
...
Sector
pulse