Path: utzoo!attcan!uunet!portal!cup.portal.com!oliver
From: oliver@cup.portal.com
Newsgroups: sci.electronics
Subject: Hard disk Ctrl Query!!!!!!
Message-ID: <6490@cup.portal.com>
Date: 14 Jun 88 06:21:54 GMT
Organization: The Portal System (TM)
Lines: 22
XPortal-User-Id: 1.1001.3624

I have an IBM AT clone....12Mhz 0 wait...and such...
I run SCO Xenix with 2-130 meg Priam drives.
What I want to do is add a third disk!!!!!
I have had no luck in locating a MFM 3+ drive controller!
I know there must be one avaible..or a way of configuring a second controller
to accept disks 2 and 3...
I want the third to be partioned DOS....

If there are no controllers avaible for 3+ how about this..
Cabeling 2 drive ones....i.e. same drive select/data/controll lines....
and have a 2 way toggle switch for the power between the drives?????
i.e. only one would recieve the 12,5 volts at once.....
Would this cause a problem with the operation of the other drive????

If so is there a way I could build a switch to connect the data/ctrl lines
between the drives.....Some sort of swichable buffer device?????

I do not know if some of the pins are bi-directional High speed......

Any help or schematics on my questions would be GREATLY APPRECIATED!!!!!!

Oliver@cup.portal.com