Tandy 1000 HX - DMA Controller

• TANDY COMPUTER PRODUCTS •
1/0 MAP SUMMARY
Block
0000-001F
0020-003F
0040-005F
0060-007F
0080-009F
00A0-00BF
00C0-00DF
00E0-01FF
0200-020F
0210-031F
0320-032F
0330-036F
0370-037F
0380-03CF
03D0-03DF
03E0-03EF
03F0-03FF
0400-FFFF
Usage
0000-000F
0020-0021
0040-0043
0060-0063
0080-0083
00A0
OOCO-OOCl
0200-0201
0378-037B
All
03Fl,03F2,F4,F5
03F8-03FF
Function
Optional DMA Function
Interrupt Controller
Timer
PIO Function
Optional DMA Page
Register
NMI Mask Register
Sound Generator
Reserved
Joystick Interface
Reserved
Reserved Hard Disk
Not Assigned
Printer
Not Used
System Video
Reserved
Floppy Disk Controller
Optional COM Port
Not Usable
45
Address
0000
0001
0002
Description
DMA Controller
IOW* = 0: Channel 0 Base and Current Address
Internal Flip/Flop = 0: Write A0-A7
Internal Flip/Flop = 1: Write A8-A15
IOR* = O: Channel 0 Current Address
Internal Flip/Flop = 0: Read A0-A7
Internal Flip/Flop = 1: Read A8-A15
DMA Controller
IOW* = 0: Channel 0 Base and Current Word Count
Internal Flip/Flop = 0: Write W0-W7
Internal Flip/Flop = 1: Write W3-W15
IOR* = 0: Channel 0 Current Word Count
Internal Flip/Flop = 0: Read W0-W7
Internal Flip/Flop = 1: Read W8-W15
DMA Controller
IOW* = 0: Channel 1 Base and Current Address
Internal Flip/Flop = 0: Write A0-A7
Internal Flip/Flop = 1: Write A8-A15
IOR* = 0: Channel 1 Current Address
Internal Flip/Flop = 0: Read A0-A7
Internal Flip/Flop = 1: Read A8-A15