Looking for a WD 1001 55 Disk controller

From: g-wright <g-wright_at_worldnet.att.net>
Date: Fri Feb 8 01:47:20 2002

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.


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.

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 Fri Feb 08 2002 - 01:47:20 GMT