Looking for a WD 1001 55 Disk controller

From: Don Maslin <donm_at_cts.com>
Date: Thu Feb 7 17:17:02 2002

On Thu, 7 Feb 2002, g-wright wrote:

> Hi Dick
>
> Sorry for the delay, just had to dig further into this. Brief history, the
> Molecular
> came to me dead in more than one area. I got the main processor going with a
> new Counter timer chip. At that point I could not Read or Write to the hard
> drives
> but the Floppy was fine. The WD 1001 SASI to MFM controller was not seeing or
> interfacing with the drives. The SASI connection seemed ok. I pulled the first
> hard drive and attached it to a PC. It formatted fine with no errors. HD's are
> Seagate ST 419 15 meg 5 1/4 Drives. So I replace the cables and looked into
> the controlled further. Could not find a true cause of the problem with the
> controller.
> It seemed to not select the drive, nor the head.
>
> I finally gave up and robbed one of my other systems of WD 1000 to try. I did
> get
> the Light to come on on the First drive when it booted. I stopped there and
> Posted
> a request for a controller in comp.os.cpm.
>
> Did not find one and after many months just setting I decided to Give the system
> an-
> other try. I tried formatting the drives. It just hung there for ever. I
> retried this on one
> of the other drives, still just hung. So I posted to this list. Since I
> received more that one Email that the other SASI to MFM controllers should work.
> I went back and looked
> further. The hanging was due to the fact that the Heads on the the Drives where
> eating the Platters and the controller just could not format the drive. After
> putting the Drive back on the PC, the PC Controller had all kinds of errors. I
> remove the cover and found the disks are bad.
>
> All three drives have the same problems. These are 306 cylinder 6 heads. I have
> about 50 Dives but none with this head and cylinder count. So I don't really
> know
> if I really do need the correct controller yet or not. I do need a seagate ST
> 419
> or similar drive though. I still would like a WD 1001 5.5. for 2 reasons. 1 to
> keep the
> Molecular original and 2 to help trouble shoot the other controller.

You should know that you can use a different ST-506/411 interface drive
instead of the failed models provided it has the same or more cylinders
and heads. You will only be able to utilize the 306/6 capacity unless
you revise some of the soft(firm?)ware, but it should provide a go/no-go
test of the controllers.

> For those following this Post. In the earlier days, the SASI interface was used
> to interface to these controllers which could control up to 4 MFM drives. They
> came in 2 sizes. One would attach directly to a 5 1/4" drive the other (which
> I have )
> was 7" x 10" and could come set up for controlling either 5 1/4 HD's or 8"
> hard drives.
> I don't know what real code differences there are between the controllers. There
> is
> a different clock and interface for the 8" hard drives. The chips used and the
> layout is
> quit different between the different boards.
>
> SASI is the early version of SCSI. It had most of the same signals and has a 50
> pin connector.
>
> One big difference is what all the pins where used for. The one here has the
> power and
> ground for the WD 1001 card supplied though the cable. Others have a separate
> power connector.
>
> For those that though I needed a PC ISA card. I guess they just used the next
> number
> in line when the made the WD 1002 xxx ISA bus to MFM controller.

There is also a WD-1002 bridge controller in 5.25" drive size. It was
used in the Kaypro-10, amongst other machines.

                                                 - don

> What is a Molecular?? It is a Z-80 basic multi user system. It had 1) Z-80
> computer that controlled the Disk system and 4 to 10 slave cards that each user
> was connected to through
> a dumb terminal. OS is CPM and Nstar.
>
>
> Thanks, again
> Jerry
>
> Jerry Wright
> JLC inc.
> g-wright_at_worldnet.att.net
>
> Richard Erlacher wrote:
>
> > What differences does your system rely on? I once had WD1000, 1001, and 1002
> > boards, all interchangeable in the TVI TS-806. I do recall there were
> > differences, but I don't recall how they might impact you.
> >
> > regards,
> >
> > Dick
> >
> > ----- Original Message -----
> > From: "g-wright" <g-wright_at_worldnet.att.net>
> > To: <classiccmp_at_classiccmp.org>
> > Sent: Wednesday, January 30, 2002 3:54 PM
> > Subject: Looking for a WD 1001 55 Disk controller
> >
> > > Hi
> > >
> > > I'm trying to get a Molecular going. it has Bad disk controller. WD
> > > 1001 55
> > >
> > > Does anyone have one of theses that they can spare.
> > >
> > > I have 1000 series But there is a difference.
> > >
> > > E-mail me at address below
> > >
> > > Thanks, Jerry
> > >
> > > Jerry Wright
> > > JLC inc.
> > > g-wright_at_worldnet.att.net (new)
> > >
> > >
>
>
Received on Thu Feb 07 2002 - 17:17:02 GMT