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IBRD Returns Garbage after Moving from a 386 System to a Pentium System

Hardware: GPIB

Problem:
I have a GPIB-PCIIA board, and I wrote a program that works great on my 386 system. I move it over to my Pentium system, and now the ibrd command returns garbage if I read 100 bytes. However, it works if I read 20 bytes.

Solution:
The problem may be due to a DMA (direct memory access) conflict. The GPIB-PCIIA board will only use DMA when the amount of data to send is over 32 bytes. This may be the reason why the 20 byte transfers work, but the 100 byte transfers do not.

Disable the DMA channel for your board: either physically in the hardware and the configuration utility, or use the ibdma 0 command in IBIC to disable DMA programmatically. If your data transfers start working again, then you know that you need to either avoid using DMA or change DMA channels.

Related Links:
Product Manuals: GPIB-PCIIA Technical Reference Manual

Attachments:





Report Date: 05/31/1996
Last Updated: 02/21/2008
Document ID: 0LUCA4RY

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