Ottawa (storing stuff) was: Re: PDP 11/34

aaaaa Jerome Fine replies: I have not been back to Ottawa very often and there were no such stores when I lived there. I lived in Ottawa for about 18 months in 1967 when I started my third job. I moved there on New Year's day and by the end of the week the temperature had dropped to minus 40. Fortunately I had been warned and with a block heater, oil dipstick heater and car warmer, the old 1965 full size Chevy (they sure did make them big back then) started without a problem. The company had an old CDC 3500 (hey - back then it was new) with a wonderful operating system that allowed many users to edit their files on-line and then submit the files as batch jobs to be executed almost immediately depending on the queue length. Now this may seem like a very limited system, but in 1967, even interactive editing was brand new. And batch jobs were normally submitted via a card deck - yep - punched cards. My initial job was to help upgrade the file structure code from a linear search of over 3000 files to a hash search of 6000 files. I wrote some code to monitor how the upgrade was being used and sure enough I predicted a system crash about an hour before it occurred - the hash algorithm was not re-using vacated file descriptors - wonderful method, inadequate implementation and checking. Next I wrote a system job to use the primitive program that copied one file at a time from/to disk/tape. The super job read all the file headers and copied all the specified files from disk to tape and attached a backup number to each file. That was the nightly backup run. During the noon lull, a five minute job backed up all the changed or new files for the morning at the next higher backup level so that any new files could also be recovered without having to backup all the files. Hey - I was asked a question about all those old companies and I mentioned Snow White (no not the virus - IBM) and the Seven Dwarfs. I remembered six and want to check if these were the correct seven? Burroughs Control Data DEC Honeywell NCR Univac Wang I don't think Xerox was one at that point in time? Sincerely yours, Jerome Fine