Getting microcode files onto a disk

[readingj@CERF.NET (John D. Reading)]

Well, that isn't the most illuminating title. 

Anyway, I just moved a disk out of a 3600 into a 3670, and I amazed 
myself - the machine actually powers up, and is able to read the
fep files on the disk. Thanks to John Delaney at delaney@xn.ll.mit.edu
for giving me some advice when it seemed like things were going bad.

The bad news is that now the machine won't boot. After the 'start'
command in the boot sequence I eventually get a flashing cursor in
the upper left corner of the screen, but nothing more - the screen
never clears, no run bars, etc. I am guessing that this is 
because I am using 3600 microcode on what is now a 3670.

So really I have two questions - does anybody know if my problem
really is the microcode, and if so, how do I get microcode files
onto this machine that I can't boot?

Thanks for any and all help,

John Reading
readingj@cerf.net