Head Switching Matrix; Write Data Circuits - Quantum Q2080 Product Description

1.3.10 HEAD SWITCHING MATRIX
Figure 1-26 is a simplified schematic of the head switching diode matrix for two heads. Refer to Figure 2-2 for
the actual matrix used.
Diodes CR7, CR6, CR14 and CR 15 are part of the head switch matrix. When the head switch IC grounds the
head centertap (HDCTO-6) the selected head is connected to the Read/Write circuits via one of the diode pairs.
None of the other diode pairs is forward biased, therefore, the other heads are isolated from the selected head.
Diodes CR5 and CR4 through CR16 and CR8 are part of the Read/Write circuits and are used to isolate the Read
and Write circuits from each other. See paragraphs 1.3.8 and 12.
r - - - - - -
I
READ
r-----~:~---------C~R81-5------~---(~~------------------~----C'~R~16--;CHANNEL
HEAD 0
/.,--~
BIFOLAR
WOUND
R/W HEAD COIL
•
HEAD 1
CR 7
HDCTO
HDCT1
CR 6 ,
HEAD SWITCH
1C
CR 4
WRITE
CURRENT
GENERATOR
~
+24V
CR 14
TRANSDUCER PCB
DRIVE CONTROL PCB
FIGURE 1-26
HEAD SWITCHING MATRIX
1.3.11 WRITE DATA CIRCUITS
Figure 1-27 is a functional block diagram of the write circuits found in the Q2080. The write enable circuit en-
sures that the
+
5V logic voltage is present; that the drive is selected, on track, and READY; and that the WRITE
GATE is active. When these conditions are met the write enable switch turns on the write current source.
REV A (01/84)
1-24