How to Clean bad Grubfirmware off DOC?

[g_friend at etang.com]

I have put a grub_firmware on my doc2000. It can drop me grub console mode but it cannot find any filesystem ,even filesystem on my harddisk. I have tried to use root(dc0,0) ,root(hd0,0),root(hd0,1)etc ,but it had no effect.It find nothing yet.

Then I face a serious situation.----How can I save my DOC ?
How can I clean the bad grub off my doc?
Before I put grub_firmware onto my DOC, I can boot from my harddisk ,floppy with DOC in place.However, after that , with DOC in place ,I even cannot boot from my floppy . It always give me grub boot .
If I  pull out it from my board , the system boot from my hard disk or floppy as usually.

Is there any way to clean the bad grubfirmware ? 
Does it mean it is waste now for me ? 
Help is urgently needed ! please give your hand  .
thanks in advance.
 







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