My Reply follows quote. On 18/04/2002 13:01 [EMAIL PROTECTED] said: >From: [EMAIL PROTECTED] (Marten van de Kraats) >Sender: [EMAIL PROTECTED] >Reply-to: [EMAIL PROTECTED] >To: [EMAIL PROTECTED] >Anyone care to tell what this is: >http://www.sigmaxi.org/amsci/Issues/Comsci02/02-05HayesF1.jpg ----------------- Painted Platters
The first disk drive was built in 1956 by IBM, as part of a business machine called RAMAC (for Random Access Method of Accounting and Control). The RAMAC drive was housed in a cabinet the size of a refrigerator and powered by a motor that could have run a small cement mixer. The core of the device was a stack of 50 aluminum platters coated on both sides with a brown film of iron oxide. The disks were two feet in diameter and turned at 1,200 rpm. A pair of pneumatically controlled read-write heads would ratchet up and down to reach a specific disk, as in a juke box; then the heads moved radially to access information at a designated position on the selected disk. Each side of each disk had 100 circular data tracks, each of which could hold 500 characters. Thus the entire drive unit had a capacity of five megabytes--barely enough nowadays for a couple of MP3 tunes. RAMAC was designed in a small laboratory in San Jose, California, headed by Reynold B. Johnson, who has told some stories about the early days of the project. The magnetic coating on the disks was made by mixing powdered iron oxide into paint, Johnson says; it was essentially the same paint used on the Golden Gate Bridge. To produce a smooth layer, the paint was filtered through a silk stocking and then poured onto the spinning disk from a Dixie cup. Use it up, wear it out, make it do or do without. -- Compact Macs is sponsored by <http://lowendmac.com/> and... SPECIAL LIST PRICES - Replacement Apple CDROMs from $19.99, MacOS 8.5 CD $79.99 PPC 5400/200Mhz 16/1.6GB/CD/ENET/L2 $119, 5+ for $99 <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> The FAQ: <http://macfaq.org/> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
