[comp.sys.ibm.pc.misc] Using two FDD controllers at once

crosenberg@cdp.UUCP (01/04/91)

Is it possible to have more than one floppy drive controller
working in a XT at once?  Here's my problem; I want to install a
1.44 meg drive in my Kaypro PC.  In order to do that I need to 
install a floppy contoller that will handle drives of this type
and upgrade to DOS 3.3.

The Kaypro doesn't have a motherboard per se.  Instead it has one
card with the processor on it and another combo floppy
controller/io card/clock/system ram card (and other proprietary
circuitry - gee am I sorry I didn't buy a clone even though this
machine has worked flawlessly for years).  Needless to say,
I can't remove this card and have a working computer.

What I would like to do is keep this card in the machine and
install a floppy controller card for my existing 360K and my new
1.44 meg drive.  I don't know how or if I can disable the
controller function from the Kaypro combo card.  But there is a
jumper on the new floppy card that allows me to select a
secondary I/O address.  It changes it from the factory setting of
3FOH-3F7H to 37OH-377H.  Would this allow both controllers to
live happily together?  How would the two drives on the new
controller card be addressed, as D: and E:? (I have a hard drive 
installed.)  Or maybe leave one drive attached to the old
controller and one to the new?

If I am barking up the wrong tree here, does someone have another
idea to let me install this 1.44 meg drive without buying a new
computer?

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poffen@sj.ate.slb.com (Russ Poffenberger) (01/05/91)

In article <140700032@cdp> crosenberg@cdp.UUCP writes:
>
>Is it possible to have more than one floppy drive controller
>working in a XT at once?  Here's my problem; I want to install a
>1.44 meg drive in my Kaypro PC.  In order to do that I need to 
>install a floppy contoller that will handle drives of this type
>and upgrade to DOS 3.3.
>
>The Kaypro doesn't have a motherboard per se.  Instead it has one
>card with the processor on it and another combo floppy
>controller/io card/clock/system ram card (and other proprietary
>circuitry - gee am I sorry I didn't buy a clone even though this
>machine has worked flawlessly for years).  Needless to say,
>I can't remove this card and have a working computer.
>
>What I would like to do is keep this card in the machine and
>install a floppy controller card for my existing 360K and my new
>1.44 meg drive.  I don't know how or if I can disable the
>controller function from the Kaypro combo card.  But there is a
>jumper on the new floppy card that allows me to select a
>secondary I/O address.  It changes it from the factory setting of
>3FOH-3F7H to 37OH-377H.  Would this allow both controllers to
>live happily together?  How would the two drives on the new
>controller card be addressed, as D: and E:? (I have a hard drive 
>installed.)  Or maybe leave one drive attached to the old
>controller and one to the new?
>
>If I am barking up the wrong tree here, does someone have another
>idea to let me install this 1.44 meg drive without buying a new
>computer?
>

Some BIOS'es will not recognize the additional drives, even if the card is
jumpered for the secondary addresses. Does the original card support 4 drives?
That is, does it have a BIG connector on the back? Most IBM PC controllers did.
If this is the case, then another card may conflict. If not, then a card that
can be set to the secondary addresses should work, unless your BIOS won't
recognize it. I had this problem with my C&T AMI BIOS 386/25 clone.

There is a solution, JDR microdevices (San Jose Ca.) sells a card that can not
only be configured for the secondary controller, but contains BIOS onboard to
install drives into the BIOS drive table. This solved my problem.

JDR advertises in more computer mags, check it out.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
1601 Technology Drive		CIS:	72401,276
San Jose, Ca. 95110             (408)437-5254