MoveToKeys
The Alto can boot-load a file beginning at any legal disk address. The
disk address is supplied by holding down a collection of keys
simultaneously while pressing the boot button. The MoveToKeys
subsystem simplifies the task of getting a .boot file to begin at a
specified physical disk location. To invoke MoveToKeys, type:
MoveToKeys filename keylist
to the Alto Executive. "filename" is the name of the file whose first
page (technically, page 1, not page 0) is to be moved to the disk
address corresponding to "keylist". The legal keys are 5, 4, 6, 7, D,
E, K, P, U, V, 0, /, and . (Remember, to type a "/" to the Alto
Executive, you must quote it.) A typical use of MoveToKeys is:
MoveToKeys Dumper DU
The file Dumper.boot could then be boot-loaded by holding down the D
and U keys while pressing the boot button.
MoveToKeys will prompt for parameters omitted from the command line and
will complain if any of the parameters supplied are illegal. (For
example, not all subsets of the set of legal keys correspond to legal
disk addresses.) In addition, the global switch /V ("verbose mode")
will give you detailed information about the pages MoveToKeys
manipulates.
MoveToKeys actually works by determining what page resides at the
specified disk address and swapping it with page 1 of the specified
file. Depending upon the pages involved, MoveToKeys must patch up
various pointers within the Alto file system to ensure a consistent
representation of files and directories. (A previous version of
MoveToKeys did not do this correctly in all cases.)
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Copyright Xerox Corporation 1979