{"id":2264,"date":"2020-11-26T11:14:30","date_gmt":"2020-11-26T10:14:30","guid":{"rendered":"https:\/\/wpethzprd.ethz.ch\/its\/?p=2264"},"modified":"2020-11-26T11:14:32","modified_gmt":"2020-11-26T10:14:32","slug":"it-find-series-3-2020-what-do-you-associate-with-it","status":"publish","type":"post","link":"https:\/\/blogs.ethz.ch\/its\/2020\/11\/26\/it-find-series-3-2020-what-do-you-associate-with-it\/","title":{"rendered":"IT Find series 3\/2020: What do you associate with it?"},"content":{"rendered":"\n

Join\nus on a journey into the past: What is this object and what do you personally\nassociate with it? Tell us your story!<\/p>\n\n\n\n

\"Magnetic
Magnetic disk, which was used at the ETH<\/em><\/figcaption><\/figure>\n\n\n\n\n\n\n\n

It is very interesting to compare prices with those back in the day. These days, you can get 4 TB of storage for less than 100 CHF. By that reckoning, the memory shouldn\u00e2\u20ac\u2122t have cost $250,000, but a mere 0.03 CHF. More comparisons are provided in the post below.<\/p>\n\n\n\n

Our history \/ our gift<\/h2>\n\n\n\n

IT\nServices received a \u201egift of considerable significance\u201c from Carl August\nZehnder in the form of an old magnetic disk. Carl August Zehnder was a full\nprofessor for IT at ETH, specialising in the development and use of large-scale\nIT systems, information management, the management of IT projects, IT training\nand IT law. He served at ETH with interruptions between 1958 and 2003.<\/p>\n\n\n\n

A handwritten note addressed to Rui Brandao stated that the disk came from ETH\u00e2\u20ac\u2122s first commercial computer, a CDC 1604A dating back to 1964. \u201eIn 1964, ETH bought its first industrially produced computer from the Control Data Corporation, the CDC 1604A. A dedicated organisation \u2013 the Data Centre \u2013 was established to operate it (ETH History<\/a>)\u201c. \u201eThe decision was ultimately made to purchase a CDC 1604A computer., The \u00e2\u20ac\u02dcControl Data Corporation\u00e2\u20ac\u2122 (CDC) was established in 1957, producing not only peripherals to supply to other computer manufacturers but also its own mainframe computers. CDC\u00e2\u20ac\u2122s first chief designer was Seymour Cray, who later went on to found his own company that would become synonymous with powerful supercomputers. \u2026 The new computer installation was located in the main building in the same area where the ERMETH was previously located (IT at ETH Zurich 1948\u20131981 Between science and service<\/a>)\u201c (in German). <\/p>\n\n\n\n

\"ETH
ETH group photo with secretaries in the IT and Data Centre groups (Photo: ETH\/Peter Staub\/ITS)<\/em><\/figcaption><\/figure>\n\n\n\n

The\n1604-A was part of the generation of computers where data was processed\nsequentially from a high-speed magnetic tape. The main computer processed one\nprogram at a time in the order that they were input, just as they had been\npreviously copied onto the magnetic tape in stacks using a separate, small\nmachine.<\/p>\n\n\n\n

Research<\/h2>\n\n\n\n

IT Services was very pleased to have received this genuine piece of history, and this disk, measuring around 66 cm in diameter, is now mounted on the wall in its ETH building. One of the IT Services staff believed that the disk was part of a cylinder that was used to hold several such disks in a stack. When trying to put some information onto the disk, some pieces of the puzzle began to come together. Some information on the CDC 1604-A was available on the ETH history page: http:\/\/www.ethistory.ethz.ch\/rueckblicke\/verwaltung\/informatikdienste\/material_dokumente\/artikel_schai2.pdf<\/a> (in German). But this page does not mention the CDC 1604-A having any magnetic disk storage. <\/p>\n\n\n\n

Inspired to play detective<\/h2>\n\n\n\n

Through Andreas Dudler, the former of Head of ITS Management, ETH Zurich, we made contact with Peter Staub of ETH\u00e2\u20ac\u2122s Contract Management and retired Deputy Director of IT Services. While he had never personally worked on the CDC 1604 or the CDC 1604A, he did have the opportunity to talk with former colleagues from back in the day who had worked on these systems. But they had no memory of any disks, neither on the 1604, nor on the 1604A. The reference manual of the 1604 and the CDC 1604-A brochure also say nothing of any magnetic disks: http:\/\/bitsavers.org\/pdf\/cdc\/160\/160-A_Peripheral_Brochure_Nov62.pdf<\/a>. <\/p>\n\n\n\n

But\nthe CDC systems from the end of the 1960s (CDC 6400 and CDC 6500) had disk\nstorage units that were massive. These systems had two disk drives (6638 and\n821) that both weighed several tons.<\/p>\n\n\n\n

According\nto the research performed by Peter Staub, the number printed on the disk\nrevealed it to be from a storage system that was connected to the CDC 6400 or\n6500. There were two type designations: 808 and 6638. <\/p>\n\n\n\n

Dieter\nGut, IT Services Quality Manager, also concluded, following in-depth internet\nresearch, that the disk might belong to a CDC 6400\/6500 system that was\npurchased when the building at Clausiusstrasse was built in 1970. The previous\nCDC 1604 had magnetic tapes.<\/p>\n\n\n\n

\"A
A long time ago (Photo: ETH\/Peter Staub\/ITS)<\/em><\/figcaption><\/figure>\n\n\n\n

\u201eThe commission made the decision in that same year [1968] to purchase a new mainframe. This was a dual system comprising the models CDC 6400 and CDC 6500 combined with a complex multi-device operating system that needed to be adapted for ETH. In 1970, the Data Centre and the computer scientists purchased the new \u201eRZ\u201c building in Clausiusstrasse, where IT Services is still situated to this day, while also bringing the new computer system into service at the same time… (IT at ETH Zurich 1948\u20131981 Between science and service<\/a>)\u201c (in German).<\/p>\n\n\n\n

Images of CDC in use at ETH<\/h2>\n\n\n\n
\"Housing
Housing for the disk storage (Photo: ETH\/Peter Staub\/ITS)<\/em><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\"Cabinet
Cabinet opened for maintenance work (Photo: ETH\/Peter Staub\/ITS)<\/em><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\"View
View of the reader heads and positioning unit (Photo: ETH\/Peter Staub\/ITS)<\/em><\/figcaption><\/figure>\n\n\n\n

Searching for comparisons<\/h2>\n\n\n\n

Comparisons\nwith today would impressively illustrate the sheer progress that technology has\nmade in the last 50 years. But alas, such a comparison isn\u00e2\u20ac\u2122t that easy. Modern\nsystems have fast but volatile memory (RAM) as well as non-volatile, slow, bulk\nstorage devices (disks, SSD). Old computers usually only had slow memory\n(magnetic-core memory, drums or disks), and these were expensive enough in\ntheir own right!<\/p>\n\n\n\n