AMSTRAD CTM644 - Disc Drive Alignment Checks (Continued)

ALIGNMENT CHECKS (cant)
Fig. 2 Waveform of T39 (Index pattern - Radial alignment)
Difference between Track 00 and 39
is within 18fJs (2')
300fJs
+114-
2F (l25kHz)
INDEX
I
.
500fJs
-
1.8ms 0.6ms
~500fJs r-01ms
100%
2F(125kHz)
INDEX I.B
2
3
4
Fig.3 Waveform of T39 (Azimuth, alignment)
120
o5 3 5 0 5 3 5 0.5
, I
BLOCK 47
I I I ....J I I
BLOCK 1 BLOCK 2 BLOCK 3
47 pair servo-patters for posi~ioning use
Fig.4 Waveform of T39
+72 - 48' +48'-72'
U IL...- --J
Index Aximuth burst
burst
2F
2F 1F
II Track
~
it ,enre'
it
.i
j
}
r-
--
r-
921J
t
90
IJ
I
-I
I _.
-I-
-
--
-
-r--
OJ.
'O.~
I
~I
L-
0.5 0.5 0.5
0.5
L-
3sJL
2.0 2.0 2.0 2.0
10.0
3.5
0.5
O.
0.5
14