Hardware manual

Changes: Several bugs in parity error detection and reporting were removed.
Version 7/5 -- August 10, 1976
Additions: The Idle procedure and corresponding static lvIdle; lvParityPhantomEnable global static; more
installation options.
Minor changes: Two bugs in PositionPage are fixed -- one permitted read-only files to be accidently
lengthened.
Version 6/5 -- July 8, 1976
Additions: (1) Several global statics have been added: AltoVersion (code for machine, build and
microcode versions), ErrorLogAddress (Ethernet address to report hardware errors), #176777 points to
the global statics.
(2) The format of Sys.Boot has been altered slightly so that Altos may be booted over the Ethernet.
Version 5/5 -- April 28, 1976
How to get it: Because version 5 introduces some incompatibilities, it is essential that several subsystems be
updated: (1) get a new Executive and Bravo 5.5 or later (these will run under version 4 or version 5 of the
operating system); (2) get Sys.Bk, Sys.Syms, Sys.Boot (under another name, e.g. NewOs.Boot); (3) install
your new system; (4) get a new version of DDS, which depends on version 5 of the operating system; (5)
get a new InstallSwat.Run and invoke it; (6) if you are a programmer, be sure to get new copies of all
definitions files (e.g. AltoFileSys.d).
Incompatibilities: (1) Most calling sequences and subroutine names for the "Bfs" routines have changed.
These changes were made in order to introduce the concept of a "disk" object, so that standard OS stream
and directory functions could be applied to non-standard disks (e.g., the Trident T80). The static
lvDiskKd has been removed.
(2) The "disk address" returned as part of a CFA or FA is now a virtual disk address. The routine
RealDiskDA can be used to convert it to a physical disk address if desired.
Minor changes: (1) The handling of the UserFinishProc has changed. The recommended procedure for
such procedures is to simply return from a finish procedure, not to call OsFinish again.
(2) Several bugs in the streams package are fixed, e.g. ReadBlock applied to a file with 511 bytes in the last
data page did not work correctly.
(3) The "new disk" refreshing procedure has been changed to use the new FTP; it is now mandatory that
this file be present on your disk when you attempt to make a brand new disk.
(4) It is now possible to change disk packs during the Install sequence; simply change packs when some
question is asked of you (exception: if you are creating a "new disk," do not change packs until told to do
so).
(5) The log functions have been made much more robust. It is now possible to delete Sys.Log and
continue operations.
(6) Numerous bugs in ReturnFrom and FramesCaller are fixed.
(7) The default number of file versions to keep is now stored in the DiskDescriptor.
(8) Wns has been changed to allow both signed and unsigned number conversion.
(9) The arguments to DeleteFile have changed slightly (only if you pass more than 2 arguments to it).
Alto Operating System May 5, 1980 36
For Xerox Internal Use Only -- December 15, 1980