Tandy 1400LT - Clock Speed

ADDRESS BIT
CONTENTS CONTROL
-
DMA PAGE REGISTER
080M
081H
082H
083H
NMI MASK REGISTER
OAOH 7
SYSTEM STATUS REGISTER
OF8N 0
1
2
3
4
5
6
7
(Write Register)
OFAH
0
1
2
3
4
5
6
7
(Read Register)
OFAH
0
1
2
3
4-7
(Write Register)
OFCH
0
1
2
3
4
5
6
7
Not used
DMA Page Register for DMA Channel
2
DMA Page Register for DMA Channel 3
DMA Page Register for DMA Channel 1
NMI Mask Register
Loop on post
Co-processor installed
RAM Size
RAM Size
Display
0
Display 1
Number of FDD
Number of FDD
LCD/CRT Exchange
FD Power Control
LCD Power Control
EL Back Light Control
Keyboard Select Switch
CRT Controller Disable
Not used
Low Battery 1 NMI MASK
LCD/CRT Switch Status
FD Power Status
LCD Power Status
EL Back Light Status
Not used
Power Save Control
Modem Power Control
Modem/RS-232C Switch
Speaker Power Control
Direct/Acoustic Switch
Clock Speed Exchange
Not used
Low Batterv 2 NMI MASK
l/active
, O/not
OO/Not means,O 1/640K
10/512K, 11/256K
OO/reserved
Ol/Color 40*25
10/Color 80*25
1 l/Monochrome
00/1 ,01/2
10/3
, 11/4
I/CRT
, O/LCD
1/ON, O/OFF
1/ON, O/OFF
1/ON
, O/OFF
l/EXT, O/INTERNAL
l/DIS
, O/ENABLE
O/MASK
1/CRT
, O/LCD
1/ON, O/OFF
1/ON, O/OFF
1/ON, O/OFF
1/ON, O/OFF
1/ON, O/OFF
1/ON, O/OFF
l/Direct,O/Acoustic
1/7.16, 0/4.77MHz
l/MODEM,O/RS-232C
O/MASK
Table 4-3. I/O Address Map (Cont.)
4-13