18 Feb
2006
18 Feb
'06
7:15 p.m.
On Saturday 18 February 2006 18:04, Kelly Leavitt wrote:
I know it can be done, I'm just not sure how. I
have an adaptec 1542B
controller that I'm using the floppy controller on.
It current has two options for the floppy controller: 3F0-3F7h or 370-377h
3F0 (001111110000) is with J8/1 open
370 (001101110000) is with J8/1 closed
I'd like to re-address this to something else, like 320 or 330 or even the
LPT or serial port addresses. Now, how the heck would I go about this? I'm
pretty good with a soldering iron, and I know how to count.
The easiest way to do this, is to trace the address lines from the ISA port to
the address decoder chip, and to swap some of the address line inputs to the
chip around.
Eg, if you swapped A7 and A6, with J8/1 closed, you'd get 3B0, swapping A7 and
A5 would get you 3D0 as an address, A7 and A4 would get 3E0, A7 and A8 get
you 2F0, A7 and A9 get you 1F0, etc.
According to the document I'm looking at, 3B0-3B7 is also used by the MDA, 3D0
is used by the CGA/EGA/VGA, 1F0 is the primary IDE controller address, and
3E0 and 2F0 seems to be generally unused.
Pat
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