SB Emulation in MS-DOS/Windows 98 B-5
Direct Memory
Access (DMA)
Channel
A DMA channel is a data channel that a device uses to transfer data directly to and
from the system memory.
Environment
Variables
Environment variables are used to pass hardware configuration information to the
software in your system. For MS-DOS, your audio card includes the following:
❑
❑
CTSYN
Environment
Variable
The CTSYN environment variable points to the location of the CTSYN.INI file, which
usually resides in the Windows directory. The syntax for this variable is as follows:
CTSYN=path
where “path” is the location of the CTSYN.INI file.
BLASTER
Environment
Variable
The BLASTER environment specifies the base I/O address, IRQ line, and DMA
channels of the SB interface. Its syntax is:
BLASTER=A220 I5 D1 H5 P330 T6
The parameters in the command are as follows:
This
Parameter
Specifies
A
xxx
SB interface’s base I/O address.
I
x
IRQ line used by the audio interface.
Table B-3:Possible default direct memory access (DMA) channel assignment.
Usage
Default DMA Channel
First DMA channel
0,
1
, 3
Second DMA channel
5
, 6, 7
