Changing size of RAMDISK

[Dhiraj <dheerubhaipompom@yahoo.com>]

Hello,
 How do I change the size of the RAMDISK to be loaded from the default 
of 4 MB. I need a 100 MB Ramdisk for something that I am doing. Is there 
no way this can be done without passing a parameter to the kernel(not 
using ramdisk as loadable module). I think rdev -r doesn't work anymore. 
 I want this to work on all 2.4 series kernels.
The kernel file ramdisk.txt says that the ramdisk size is changed as 
required but when I tried to use a ramdisk (pre-exsiting ram8) and tried 
to dd 8192 bytes to it, it reported error after 4096 bytes.
thanks a lot
Dhiraj