Subject: RE: Bubble memory devices From: "Gavin Melville" <gavin.melville at acclipse.co.nz> Date: Mon, 18 Feb 2008 15:11:19 +1300 To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Hi, Bubble was very, very expensive, and about that time SRAM was becoming available. I don't have any complete 7110's left -- Intel took them all back, but I do have the internals. Inside the various coils was a garnet "chip" and under a good microscope you can see the Chevrons that steered the magnetic bubbles.

The problem for the company I worked for at the time was temperature -- at about 0 deg C all the bubbles wandered off. I still clearly remember the Intel FAE telling me, with great conviction "you still have every bubble -- none have been lost". My explanantion that that was of little use -- I don't know which byte or address they belong to was lost on him.

Steering the little bubbles around was fun -- you could rotate the majority loop, rotate the all minority loops, and replicate from one loop to the other. Random access it wasn't...

Because of supposed military uses Intel were REAL serious about security -- they had to know where they all were, who the customers were etc.

> -----Original Message----- > From: cctalk-bounces at classiccmp.org > [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Andrew Burton > Sent: Monday, February 18, 2008 1:42 PM > To: cctalk at classiccmp.org > Subject: Bubble memory devices > > > Hi, > > Whilst waiting for a video to download (I'm still on dial-up) > I decided to have a flick through an issue of 80 > Microcomputing. It's issue 10 (October 1980) and inlcudes an > article about the row about whether the US government and/or > patent office should honour copyrights for computer software. > > Anyway, on page 46 I stumbled across an interesting article > (called "A Slow Road To Bubble Memories") about bubble > memory. The main bubble memory manufacturers of the time were > Intel Corp., Texas Instruments and Rockwell Int. The article > also mentions that Rockwell had a bubble system, a 256K bit > board, available for $1,800. Meanwhile Intel had a bubble > system in kit form - 7110-1 Magnetic Memory board came with > all control and support circuitry - and sold for $2,000. > > What happened to bubble memory? Did it die out due to the > costs, or did people prefer to use cassettes, disks etc. instead? > > > Regards, > Andrew B > aliensrcooluk at yahoo.co.uk > > >