5 Jun
2005
5 Jun
'05
8:12 p.m.
One of the CDC 9404, PN 75744025 8" floppy drives in my MDS-800 is have a problem
becoming "Ready". I swapped drives and it is the drive. Does anyone have a
maintenance manual or any documentation on this drive or the cabling to the MDS.
Bob
5 Jun
5 Jun
8:28 p.m.
From: "xyz" <rsnats at bellsouth.net>
Sent: Sunday, June 05, 2005 10:12 PM
One of the CDC 9404, PN 75744025 8" floppy drives
in my MDS-800 is have a
problem becoming "Ready". I swapped drives and it is the drive. Does
anyone have a maintenance manual or any documentation on this drive or the
cabling to the MDS.
Bob
http://www.bitsavers.org/pdf/cdc/discs/75897465_9404B_floppyMaint.pdf
Randy
www.s100-manuals.com
6 Jun
6 Jun
4:21 a.m.
Thanks Randy.
Themanual at the web site is for a 9404-B. It has a lot of helpful
information, but the printed circuit board is more modern. I have traced
out some of the circuitry and it appears the even the pinouts from the 50
pin connector do not match those of the 9404-B. That surprised me.
Bob
----- Original Message -----
From: "Randy McLaughlin" <cctalk at randy482.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Sunday, June 05, 2005 10:28 PM
Subject: Re: MDS CDC Disk Drive Documentation
From: "xyz" <rsnats at bellsouth.net>
Sent: Sunday, June 05, 2005 10:12 PM
> One of the CDC 9404, PN 75744025 8" floppy drives in my MDS-800 is have
a
> problem becoming "Ready". I swapped
drives and it is the drive. Does
> anyone have a maintenance manual or any documentation on this drive or
the
cabling to the
MDS.
Bob
http://www.bitsavers.org/pdf/cdc/discs/75897465_9404B_floppyMaint.pdf
Randy
www.s100-manuals.com
8:06 a.m.
From: "xyz" <rsnats at bellsouth.net>
Sent: Monday, June 06, 2005 6:21 AM
Thanks Randy.
Themanual at the web site is for a 9404-B. It has a lot of helpful
information, but the printed circuit board is more modern. I have traced
out some of the circuitry and it appears the even the pinouts from the 50
pin connector do not match those of the 9404-B. That surprised me.
Bob
<snip>
I've got a paper manual from the Radio Shack model II technical manual but I
bet it's also for the -B.
I'll look and let you know.
Sorry I assumed Al had what you needed.
If you find the right manual please pass it on to Al or myself.
Randy
www.s100-manuals.com
9:50 a.m.
From: "Randy McLaughlin" <cctalk at randy482.com>
Sent: Monday, June 06, 2005 10:06 AM
From: "xyz" <rsnats at bellsouth.net>
Sent: Monday, June 06, 2005 6:21 AM
My hardcopy is also a -B.
Randy
Thanks Randy.
Themanual at the web site is for a 9404-B. It has a lot of helpful
information, but the printed circuit board is more modern. I have
traced
out some of the circuitry and it appears the even the pinouts from the 50
pin connector do not match those of the 9404-B. That surprised me.
Bob
<snip>
I've got a paper manual from the Radio Shack model II technical manual but
I bet it's also for the -B.
I'll look and let you know.
Sorry I assumed Al had what you needed.
If you find the right manual please pass it on to Al or myself.
Randy
www.s100-manuals.com
7:07 p.m.
Good News,
I traced the signals back to the index pulse driving a flipflop. The pulse
was not large enough to trigger the FF so I cleaned and peaked the sensor's
output. The drive now becomes ready and seeks.
Bad News,
The drives still want boot from the floppy, but I am closer
Bob
----- Original Message -----
From: "Randy McLaughlin" <cctalk at randy482.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Monday, June 06, 2005 11:50 AM
Subject: Re: MDS CDC Disk Drive Documentation
From: "Randy McLaughlin" <cctalk at
randy482.com>
Sent: Monday, June 06, 2005 10:06 AM
> From: "xyz" <rsnats at bellsouth.net>
> Sent: Monday, June 06, 2005 6:21 AM
>
>> Thanks Randy.
>>
>> Themanual at the web site is for a 9404-B. It has a lot of helpful
>> information, but the printed circuit board is more modern. I have
>> traced
>> out some of the circuitry and it appears the even the pinouts from the
50
>> pin connector do not match those of the
9404-B. That surprised me.
>>
>> Bob
> <snip>
>
> I've got a paper manual from the Radio Shack model II technical manual
but
I bet it's
also for the -B.
I'll look and let you know.
Sorry I assumed Al had what you needed.
If you find the right manual please pass it on to Al or myself.
Randy
www.s100-manuals.com
My hardcopy is also a -B.
Randy
3:21 p.m.
One of the CDC 9404, PN 75744025 8" floppy drives in my MDS-800 is have =
a problem becoming "Ready". I swapped drives and it is the drive. =
Does anyone have a maintenance manual or any documentation on this drive =
or the cabling to the MDS.
I posted wirelists of all the bits of cabling from the double-density
controller board to the drives a couple of months back (I think in a
reply to one of JoeR's messages). That should be in the archives
-tony
7138
days inactive
7139
days old
6 comments
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