Šarūnas, >What was the transfer speed for the latter? Seek times for both? One >thing is to store data, another --- getting it, or finding it at all, >in time, that is...
Well, at first I was simply going to write you about how I was talking about a 30+ year old disk drive from a computer company that has been defunct for over ten years, but then I did a google and on the first try, in less than two seconds, I came up with this: http://www.columbia.edu/acis/history/rp06.html I find the history interesting, because they say the RP06 was equivalent to an IBM 3330 Model II disk drive, and I remembered them being about one-quarter GB, but the history says they are only 178 MBytes formatted. I do notice they are talking about 36 bit words for a DEC 20, so formatting could definitely change the capacity of the disk pack, but in further checking I think that the RP06 was about 176-178 MBytes, so the size ratio to the two Terabyte disks is even greater than 8000 times. :-) The page also talks about "upgrading" the drives to "sealed", which would allow a greater capacity (probably by also replacing some heads). Note that the unsealed RP06 drives had a removable disk platter that had 20 heads and 19 recording surfaces. The twentieth head was used for timing marks (i.e. "real" formatting, not just creating a stub directory structure). You are right about the concept of "holding" vs "finding". The machines of the day (VAXen, PDP-11/70s) were machines that typically had 1-4 Mbytes (mostly toward the lower end) of main memory and cycle times of one million CISC instructions per second. But the other concept, of "finding it in time", leads to a discussion of batch processing, where times were not measured by the impatient drumming of fingers on the desktop versus really good indexing for 'searching', "capacity" vs "speed". Even today there are many applications that simply need to have the data online for that one weird old guy who would like to see it again every ten, fifteen or thirty years. Warmest regards, maddog -- Jon "maddog" Hall Executive Director Linux International(R) email: [EMAIL PROTECTED] 80 Amherst St. Voice: +1.603.672.4557 Amherst, N.H. 03031-3032 U.S.A. WWW: http://www.li.org Board Member: Uniforum Association Board Member Emeritus: USENIX Association (2000-2006) (R)Linux is a registered trademark of Linus Torvalds in several countries. (R)Linux International is a registered trademark in the USA used pursuant to a license from Linux Mark Institute, authorized licensor of Linus Torvalds, owner of the Linux trademark on a worldwide basis (R)UNIX is a registered trademark of The Open Group in the USA and other countries. _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
