Tandy 1400LT Service Manual page 51

ADDRESS BIT CONTENTS CONTROL
PRINTER CONTROL
378H
379H
37AH
VIDEO CONTROLLER
3DOH
3DFH
I
FLOPPY DISK CONTROLLER
3F2H 0
1
2
3
4
5
6
7
3 F4H
3F5H
COMl CONTROL
3FSH(Write)
3F8H(Read)
3F8H
3F9H
3F9H
3FAH
3FBH
3FCH
3FDH
3FEH
Printer Data Output Port
Printer Status Port
Printer Control Port
V6355 Control Registers
Drive Select
Drive Select
Not FDC Reset
Enable INT
&
DMA Request
Drive A Motor ON
&
In-use
Drive B Motor ON & In-use
Drive C Motor ON & In-use
Drive D Motor ON & In-use
FDC Main Status Register
FDC Data Register
Tx Buffer (DLAB
=
0)
Rx Buffer (DLAB
=
0)
Divisor Latch LSB (DLAB
=
1)
Divisor Latch MSB (DLAB
=
1)
Interrupt Enable Register (DLAB
=
0)
Interrupt Identification Registers
Line Control Register
Modem Control Register
Line Status Register
Modem Status Register
OO/DRIVE A
Ol/DRIVE B
lO/DRIVE C
ll/DRIVE D
1 / O N , O/OFF
1 / O N , O/OFF
1/ON
,
O/OFF
1/ON
,
O/OFF
Table 4-3. I/O Address Map (Cont.)
4-14