Page:CTSS programmer's guide.djvu/43

 the input tape control cards, before producing the requested dump tapes. In addition, the current history tapes are extended by the over-age files and any files which the user has asked to be deleted; corresponding file directory entries are marked along with the date dumped and the history tape position. Finally, the dump program produces an output tape for the 1401 of output requested by the dump control cards, both those submitted directly and those generated from consoles. This output consists of: BCD printing, BCD and binary cards, prefix-7 binary cards (for convenient and safe reloading of the disk), and those remaining control cards not acted upon which were produced at the consoles and left by the supervisor. The latter control cards, which may include requests to restore to the disk some files which have been displaced to the history tapes, are sorted for systematic retrieval in the next editing phase. Requested disk output of all forms will be kept at the Center for a period of only 2 weeks before being disposed of. During this time, it is the user's responsibility to pick up his output at the Center.

The second phase of the procedure is that of loading the disk. The load-edit program is placed in the 1401 card reader, along with the control cards produced by the 7090 dump-edit program, as well as those load-control cards and input card decks submitted to the Center Dispatching Area. Input card decks, after they have been used by the edit program, will be placed in the Output Request Section of the Center and have a similar 2-week lifetime before disposal. By means of a special 1401 program, the above input is used to write a 7090 input tape which includes those files requested from history tapes. The latter is accomplished by the 1401 load-control cards produced by the 7090, which log on the 1401 printer giving the 1401 operator detailed instructions on the mounting and dismounting of history tapes. Finally the 7090 load-edit program, with input data, is run as a standard FMS job, where the input edit data and the previous disk dump tapes form the input.

The user will be able by a  command to retrieve his file from a history tape and replace it on the disk while at his console. This command will first give the user an estimate of the minutes of 7090 29