Direct Memory Access (DMA) Channels and Descriptions (104418)
The information in this article applies to:
- Microsoft MS-DOS operating system 2.11
- Microsoft MS-DOS operating system 3.1
- Microsoft MS-DOS operating system 3.2
- Microsoft MS-DOS operating system 3.21
- Microsoft MS-DOS operating system 3.3
- Microsoft MS-DOS operating system 3.3a
- Microsoft MS-DOS operating system 4.0
- Microsoft MS-DOS operating system 4.01
- Microsoft MS-DOS operating system 5.0
- Microsoft MS-DOS operating system 5.0a
- Microsoft MS-DOS operating system 6.0
- Microsoft MS-DOS operating system 6.2
- Microsoft MS-DOS operating system 6.21
- Microsoft MS-DOS operating system 6.22
This article was previously published under Q104418 SUMMARY
A direct memory access (DMA) channel provides high speed data transfer
between a peripheral device, such as a disk drive controller, and
memory without intervention by the CPU. Listed below are the DMA
channels for the IBM PC and XT class machines and the IBM AT and above
class machines.
IBM PC and XT
-------------
DMA Channel Description
---------------------------------------------------
0 Dynamic RAM Refresh
1 Reserved
2 Floppy Disk Controller
3 Hard Disk Controller
IBM AT and Above
----------------
DMA Channel Description
---------------------------------------------------
0 Reserved
1 SDLC Controller
2 Floppy Disk Controller
3 Hard Disk Controller
4 Cascade from DMA channels 0 - 3
5 Reserved
6 Reserved
7 Reserved
REFERENCES
"The Handbook For Microcomputer Technicians," by Peter N. Bernstock,
ISBN 0-89435-424-8
The products included here are manufactured by vendors independent of
Microsoft; we make no warranty, implied or otherwise, regarding these
products' performance or reliability.
| Modification Type: | Major | Last Reviewed: | 5/6/2003 |
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| Keywords: | KB104418 |
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