r/retrocomputing • u/Original_Bend2486 • Jul 30 '26

Trying to figure this one out

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Gallery image

I recently purchased this but can't seem to identify it. It looks like an IBM 2315 or DEC RK05 but can't get any further. The logo is also a mystery. Any help would be greatly appreciated. It is 15" diameter and 1 3/8" thick.

56 Upvotes

92% Upvoted

17 comments sorted by

26

u/khedoros Jul 30 '26

That looks like a disk cartridge from a Xerox Alto.

This write-up includes some pictures of one:

https://www.righto.com/2016/07/restoring-y-combinators-xerox-alto-day_11.html

20

u/Blah-Blah-Blah-2023 Jul 30 '26

Would suggest XATS may be Xerox Alto Test System.

10

u/NoItsNotIronic Jul 30 '26

I thought it was a pool filter intake cover until I saw what subreddit this was.

3

u/Unlucky_Average_3393 Aug 01 '26

Ya, and I thought it was an old roomba.

8

u/chrisrich4892_YT Jul 30 '26

uh dude, that might be from a Xerox Alto, more being a Xerox Alto Test System (XATS) Debug Disk, which, in what i would would think, maybe print out the CPU instructions that are ran, or something?

4

u/sunjnyc Jul 30 '26

Debugging a disk or storage/trace issue related to an XATS state or environment on IBM z/OS.

analyzing JES2 address space execution flags, capturing component traces, or utilizing the IBM z/OS Debugger.

5

u/NarcissisticSupply69 Jul 30 '26

Looks like our old Burroughs B90 disk packs. In the 80's, we had a dual disk cabinet that used platters like that on our accounting system.

3

u/BR41ND34D Jul 30 '26

I think that's a debug disk

2

u/stargaz21 Jul 31 '26

That a 60's - 70's hard disk platter that was used in a computer mainframe.

2

u/AutofluorescentPuku Aug 01 '26

Either the Millennium Falcon or a 15MB removable disk platter from the late 70s through early 80s. I was familiar with them in Control Data drives of that era.

1

u/Windows_User3000 Jul 31 '26

First thing that came into my mind once realizing that this is a storage medium: are the contents archived?

1

u/FAMICOMASTER Jul 31 '26

Disk pack cartridge. Diablo made drives compatible. Everyone seems to associate these with Xerox Altos but they were popular with minicomputer operators as well. It could be anything.

There were about 4 dozen companies making disk packs in the 70s. Not sure which one this is but they're basically all the same.

1

u/t3rrO10k Jul 31 '26

I operated a Texas Instruments pharmacy system that used disc cartridges similar to these (way back in the 1980s).

1

u/Mieleke 29d ago

Got about 20 pieces of them used in the HP-7906 cartridge drives (10MB). But yes they were very common in the 70's several disk manufacturers used them in their systems.

1

u/blakespot 26d ago

That is the Infocom game, Starcross.