10 Dec
2025
10 Dec
'25
7:02 p.m.
Hey all -
I came across a big box of 12 of these disks which my dad acquired through
work back in the 70s, and squirreled them away in the attic after they had
copied the data. 4 of them have a broken metal access door. I opened one of
the broken ones (in a clean of an environment as possible) to see what was
going on inside. It looks like the door is held on by plastic divets that
have broken off. They might be able to be repaired with small screws. I
have no idea if these are functional or not. I am offering them up for free
for anyone that can use them. I'm willing to ship or you pick up in San
Diego.
Here is a link to photos of them:
https://drive.google.com/drive/folders/1wnzqjAtiq44MGU-wDJR-AQdzu-Mkyii8?us…
-Kurt
11 Dec
11 Dec
9:33 a.m.
On Dec 10, 2025, at 8:02 PM, Kurt Nowak via cctalk
<cctalk(a)classiccmp.org> wrote:
Hey all -
I came across a big box of 12 of these disks which my dad acquired through
work back in the 70s, and squirreled them away in the attic after they had
copied the data. 4 of them have a broken metal access door. I opened one of
the broken ones (in a clean of an environment as possible) to see what was
going on inside. It looks like the door is held on by plastic divets that
have broken off. They might be able to be repaired with small screws. I
have no idea if these are functional or not. I am offering them up for free
for anyone that can use them. I'm willing to ship or you pick up in San
Diego.
Here is a link to photos of them:
https://drive.google.com/drive/folders/1wnzqjAtiq44MGU-wDJR-AQdzu-Mkyii8?us…
-Kurt
They look like 12 sector packs, so while they probably are not RK05 formatted given IBM
ancestry they would likely be useable in an RK05 drive. The "access door" is
just a shutter for the air inlet, to keep the dust out. If the door is missing the
platter isn't as protected but would still be useable. That assumes of course that
there is no contact between door and platter when the pack is installed in a drive.
If I had an RK05, or a 360 model 44 :-) I'd be interested.
What system were these used on? I see a label that says "1130".
paul
12:04 p.m.
Well I've not placed one into an 1131 console since oh... the summer of
1968, but they do look 1130 disks.
The 1131 drive is quite mechanically complex (voice coil and ratchet),
watched an IBM SE (in white shirt and tie, with Tek portable scope) open
one for servicing.
See more at http://ibm1130.org
Contrast with the Wang calculator disk drive which looks like a little
top loader, you took the platter out of a paper sleeve, gave it little
wet pad wipe and dropped it onto the spindle. No cartridge at all. At
the time I was struck by the different platter packaging approaches.
-Robert
On 12/11/25 7:33 AM, Paul Koning via cctalk wrote:
On Dec 10, 2025, at 8:02 PM, Kurt Nowak via
cctalk <cctalk(a)classiccmp.org> wrote:
Hey all -
I came across a big box of 12 of these disks which my dad acquired through
work back in the 70s, and squirreled them away in the attic after they had
copied the data. 4 of them have a broken metal access door. I opened one of
the broken ones (in a clean of an environment as possible) to see what was
going on inside. It looks like the door is held on by plastic divets that
have broken off. They might be able to be repaired with small screws. I
have no idea if these are functional or not. I am offering them up for free
for anyone that can use them. I'm willing to ship or you pick up in San
Diego.
Here is a link to photos of them:
https://drive.google.com/drive/folders/1wnzqjAtiq44MGU-wDJR-AQdzu-Mkyii8?us…
-Kurt
They look like 12 sector packs, so while they probably are not RK05
formatted given IBM ancestry they would likely be useable in an RK05 drive. The
"access door" is just a shutter for the air inlet, to keep the dust out. If the
door is missing the platter isn't as protected but would still be useable. That
assumes of course that there is no contact between door and platter when the pack is
installed in a drive.
If I had an RK05, or a 360 model 44 :-) I'd be interested.
What system were these used on? I see a label that says "1130".
paul
11:02 a.m.
Thanks for all the info, especially info on the spring loaded access door.
The vacuum venting makes sense but I'm still perplexed as to how the
read/write head gets access to the magnetic surface. As I stated in my
original posting, 4 of them seem to have broken off. Do you think it's best
to open the rest of the broken ones up (in a very clean dust free area) and
remove them or leave them in there flopping around risking damage during
transit? They are pretty easy to open up.I was thinking of carefully taping
shut the opening with masking tape and a small patch of plastic.
Also, they have been claimed already, sorry. A portion will be donated to
CHM.
-Kurt
On Fri, Dec 12, 2025 at 12:33 AM Christian Corti via cctalk <
cctalk(a)classiccmp.org> wrote:
On Wed, 10 Dec 2025, Kurt Nowak wrote:
I came across a big box of 12 of these disks
which my dad acquired
through
work back in the 70s, and squirreled them away in
the attic after they
had
These are disk cartridges from an IBM 1130 system.
Christian
13 Dec
13 Dec
12:28 p.m.
On Dec 12, 2025, at 12:02 PM, Kurt Nowak via cctalk
<cctalk(a)classiccmp.org> wrote:
Thanks for all the info, especially info on the spring loaded access door.
The vacuum venting makes sense but I'm still perplexed as to how the
read/write head gets access to the magnetic surface.
The metal lid on the bottom has nothing to do with the heads.
The heads access the cartridge via the opening in the rear, which is normally covered by a
plastic cover that latches in a groove in the bottom cover of the cartridge. Pressure
against the top edge of the cover (horizontally towards the spindle) releases it, and it
is then pushed upward, with the long plastic strip that extends most of the way over the
top of the cartridge flexing to allow that. In the drive, this hs done by an arm that
swivels upward to produce that horizontal-then-vertical pressure.
You can only see this if you insert a pack into a drive that has the top cover removed,
otherwise it happens invisibly in the back of drive as you insert the pack through the
loading slot.
paul
12:30 p.m.
On Dec 12, 2025, at 12:02 PM, Kurt Nowak via cctalk
<cctalk(a)classiccmp.org> wrote:
.... Do you think it's best
to open the rest of the broken ones up (in a very clean dust free area) and
remove them or leave them in there flopping around risking damage during
transit? They are pretty easy to open up.I was thinking of carefully taping
shut the opening with masking tape and a small patch of plastic.
I would suggest not messing with them. Just store them in a container that keeps dust
out. At the time I used these packs, normal practice was to store them in oversized
zip-lock bags if you wanted extra protection, or simply in the open in a rack similar to
what tape reels are stored in (just with wider slots).
paul
1
days inactive
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days old
6 comments
4 participants
participants (4)
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Christian Corti -
Kurt Nowak -
Paul Koning -
Robert Marinelli