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Interface
System
110 C hannel Interface
All signals are TTL-compatible:
Most Positive Up Level
+ 5.5 Vdc
Least Positive Up Level
+2.7Vdc
Most Positive Down Level
+0.5 Vdc
Least Positive Down Level
-0.5Vdc
The following lines are used by this adapter.
+DO-7 (Bidirectional, Load: 1 74LS, Driver: 74LS 3-state):
These eight lines form a bus through which all
commands, status, and data are transferred. Bit 0 is
the low-order bit.
+
AO-9 (Adapter input, Load: 1 74LS): These 10 lines form an
~
address bus by which a register is selected to receive or
supply the byte transferred through lines DO-7. Bit 0
is the low-order bit.
+AEN
(Adapter input, load: 1 74LS): The content of lines
A0-9 is ignored if this line is active.
-lOW
(Adapter input, Load: 1 74LS): The content of lines
DO-7 is stored in the register addressed by lines AO-9
or DACK2 at the trailing edge of this signal.
-lOR
(Adapter input, Load: 1 74LS): The content of the
register addressed by lines AO-9 or DACK2 is gated
onto lines DO-7 when this line is active.
-DACK2 (Adapter input, load: 2 74LS): This line being active
degates output DRQ2, selects the FDC data register as
the source or destination of bus DO-7, and indirectly
gates T / C to IRQ6.
Diskette Adapter 19
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