🚀 go-pugleaf

Hello,

after opening a original IBM AT that I received a while
ago I found a card that I would like to know more about
but of course I never received the manuals with the
computer.

The card is a full length AT card that drives the
floppy and the harddisks. It is marked AT-2000 and
has no others names on it. It has a number of jumpers
(about 9 I think). Can anybody tell me what this is, and
more important what the jumper settings mean, I need to hook
the harddrives up to another controller (RLL instead of
MFM) but can not get the system to boot if I just disconnect
the harddrives from the current controller.
Is one of the jumpers for turning drive B: off as shadow of
A: ???

Another question is: Is there a magic key to press during
boot time on a genuine IBM AT (8 Mhz / 512 KB) to get some
sort of installation menu?

Last: Is there a backup'ed clock on the motherboard, if so
I found the battery that goes with it but is dead, does
anyone know the properties of this battery????

All other basic information about an IBM AT or references
to documents are more than welcome...

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Fer F.de Jong       European Organization For Nuclear Research
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