Changing Hardware Configuration Settings
Appendix C
AT-GPIB/NI-488M/AT&T UNIX
C- 10
© National Instruments Corp.
You can also physically disconnect the AT-GPIB from the DMA channel
lines of the PC AT bus by removing the two jumpers (although this is not
required), if you do not want to use DMA for GPIB transfers. The jumpers
can be stored on the board in the positions shown in Figure C-5.
Removing the jumpers disables the ability of the AT-GPIB to assert a
DRQ line on the PC AT I/O channel. Make sure that you make a
corresponding change to the software DMA channel setting during the
software installation discussed in Chapter 3.
Key
= used to set the interrupt line
• •
• •
• •
• •
DRQ7
DACK7
DRQ6
DACK6
DRQ5
DACK5
15
14
12
11
10
IRQ
•
•
Figure C-5. DMA Jumper Setting for No DMA Channel