WAITS on-disk file structure - Revision history

Jnc: Re-classify

2024-10-13T00:24:52Z

Re-classify

Larsbrinkhoff: /* SAT */ SAT header.

2023-06-15T12:09:54Z

‎SAT: SAT header.

Larsbrinkhoff: /* UFD */ Note long format in table.

2023-06-15T06:04:09Z

‎UFD: Note long format in table.

Larsbrinkhoff: /* UFD */ Typo.

2023-06-15T06:00:00Z

‎UFD: Typo.

Larsbrinkhoff: Link to RALF on GitHub.

2023-06-15T05:54:21Z

Link to RALF on GitHub.

Larsbrinkhoff: Credit.

2023-06-15T05:41:54Z

Credit.

Larsbrinkhoff: Location of SAT and MFD.

2023-06-15T05:40:27Z

Location of SAT and MFD.

Larsbrinkhoff: Start adding information about the format in use around 1974.

2023-06-15T05:30:16Z

Start adding information about the format in use around 1974.

Larsbrinkhoff: Table for RIB data.

2023-06-14T18:40:12Z

Table for RIB data.

Larsbrinkhoff: /* UDP */ Disk not data.

2023-06-14T17:07:17Z

‎UDP: Disk not data.

@@ Line 1: / Line 1: @@
-{{stub}}
+This is a description of the [[WAITS]]' on-disk file structure.  It tries to describe the variants in use with 3300-2 packs on a [[KA10]] around 1974, and with RP06 and RP07 packs on a [[KL10]] in 1988.  Much of this information comes from the last version of Ralph Gorin's RSKINI, which is used to format a disk pack, and [[Stanford Artificial Intelligence Laboratory|SAIL]] alumnus Bruce Baumgart's tool [https://github.com/saildart/waits-disk-kits RALF].
 == Disk area units and geometry ==
@@ Line 194: / Line 192: @@
 A '''UDP''' is a ''User Disk Pack''.  This is a removable disk pack that holds data for a single user.  WAITS will have at least one disk drive available for mounting UDPs.
 [[Category: PDP-10 Disk Formats]]
 [[Category: File Systems]]

@@ Line 81: / Line 81: @@
 The '''SAT''' is the ''Storage Allocation Table''.  There is only one SAT for the entire structure.  It can be on any unit.  In the 1974 format, the SAT is at the logical beginning of the disk, i.e. on the first track of the first cylinder of the first unit.  In the 1988 format, the location of the SAT is in the HOM block.
-The SAT is a bit array, indexed by ''block'' address.  '''1''' means free, and '''0''' means allocated.  Bits inside words are MSB, i.e. bit 0 by PDP-10 convention, first
+The SAT starts with a header consisting of some data fields.  After that comes a bit array, indexed by ''block'' address.  '''1''' means free, and '''0''' means allocated.  Bits inside words are MSB, i.e. bit 0 by PDP-10 convention, first
 All disk areas in use, including HOM and BAT blocks, SAT, and swapping area, must be allocated in the SAT.
 == Swapping area ==

@@ Line 131: / Line 131: @@
 == UFD ==
-A '''UFD''' is a ''User File Directory'', corresponding to a user '''PPN''', ''project-programmer number''.  The UFD is a file with extension UFD in the [1,1] directory.  It consists of a sequence of '''UFD entries''' which are either 4 or 16 words long, depending on whether the monitor was assembled with '''FTLUFD''' enabled or not.  WAITS changed to the long format late 1977.
+A '''UFD''' is a ''User File Directory'', corresponding to a user '''PPN''', ''project-programmer number''.  A UFD is a file with extension UFD in the [1,1] directory.  It consists of a sequence of '''UFD entries''' which are either 4 or 16 words long, depending on whether the monitor was assembled with '''FTLUFD''' enabled or not.  WAITS changed to the long format late 1977.
 {| class="wikitable"
@@ Line 143: / Line 143: @@
 |-
 | 3 || ''Record'' address of the first block in the file
 |-
 | 4 || File length, in words

@@ Line 131: / Line 131: @@
 == UFD ==
-A '''UFD''' is a ''User File Directory'', corresponding to a user '''PPN''', ''project-programmer number''.  The UFD is a file with extension UFD in the [1,1] directory.  It consists of a sequence of '''UFD entries''' which are either 4 or 16 words long, depending on whether the monitor was assembled with '''FDLUFD''' enabled or not.  WAITS changed to the long format late 1977.
+A '''UFD''' is a ''User File Directory'', corresponding to a user '''PPN''', ''project-programmer number''.  The UFD is a file with extension UFD in the [1,1] directory.  It consists of a sequence of '''UFD entries''' which are either 4 or 16 words long, depending on whether the monitor was assembled with '''FTLUFD''' enabled or not.  WAITS changed to the long format late 1977.
 {| class="wikitable"

@@ Line 1: / Line 1: @@
 {{stub}}
-This is a description of the [[WAITS]]' on-disk file structure.  It tries to describe the variants in use with 3300-2 packs on a [[KA10]] around 1974, and  with RP06 and RP07 packs on a [[KL10]] in 1988.  Much of this information comes from the last version of Ralph Gorin's RSKINI, which is used to format a disk pack, and [[Stanford Artificial Intelligence Laboratory|SAIL]] alumnus Bruce Baumgart's tool RALF.
+This is a description of the [[WAITS]]' on-disk file structure.  It tries to describe the variants in use with 3300-2 packs on a [[KA10]] around 1974, and  with RP06 and RP07 packs on a [[KL10]] in 1988.  Much of this information comes from the last version of Ralph Gorin's RSKINI, which is used to format a disk pack, and [[Stanford Artificial Intelligence Laboratory|SAIL]] alumnus Bruce Baumgart's tool [https://github.com/saildart/waits-disk-kits RALF].
 == Disk area units and geometry ==

@@ Line 79: / Line 79: @@
 == SAT ==
-The '''SAT''' is the ''Storage Allocation Table''.  There is only one SAT for the entire structure.  It can be on any unit.
+The '''SAT''' is the ''Storage Allocation Table''.  There is only one SAT for the entire structure.  It can be on any unit.  In the 1974 format, the SAT is at the logical beginning of the disk, i.e. on the first track of the first cylinder of the first unit.  In the 1988 format, the location of the SAT is in the HOM block.
 The SAT is a bit array, indexed by ''block'' address.  '''1''' means free, and '''0''' means allocated.  Bits inside words are MSB, i.e. bit 0 by PDP-10 convention, first
@@ Line 125: / Line 125: @@
 == MFD ==
-The '''MFD''' is the ''Master File Directory''.  There is only one MFD for the entire structure.  It can be on any unit.
+The '''MFD''' is the ''Master File Directory''.  There is only one MFD for the entire structure.  It can be on any unit.  In the 1974 format, the MFD is on the second track of the first cylinder of the first unit.  In the 1988 format, the location of the MFD is in the HOM block.
 The MFD is the [1,1] directory.  Each file in the MFD is a UFD with a file name matching that UFD's PPN.  The MFD itself is the file '  1  1'.UFD[1,1].

@@ Line 1: / Line 1: @@
 {{stub}}
-This is a description of the [[WAITS]]' on-disk file structure; in particular the version used with RP06 and RP07 packs on a [[KL10]] in 1988.  There are differences against the [[KA10]] 1974 data structures.  Much of this information comes from the last version of RSKINI, which is used to format a disk pack.
+This is a description of the [[WAITS]]' on-disk file structure.  It tries to describe the variants in use with 3300-2 packs on a [[KA10]] around 1974, and  with RP06 and RP07 packs on a [[KL10]] in 1988.Much of this information comes from the last version of RSKINI, which is used to format a disk pack, and [[Stanford Artificial Intelligence Laboratory|SAIL]] alumnus Bruce Baumgart's tool RALF.
 == Disk area units and geometry ==
@@ Line 17: / Line 17: @@
 == HOM blocks ==
-There are two '''HOM''' blocks.  They are both at the logical beginning of the disk, i.e. on the first track of the first cylinder of the first unit.  The first block is sector 1 (starting from 0), and the second is 10 (decimal).  There are no HOM blocks on the other units.
+In the 1988 format, there are two '''HOM''' blocks.  The 1974 format has no HOM blocks.  They are both at the logical beginning of the disk, i.e. on the first track of the first cylinder of the first unit.  The first block is sector 1 (starting from 0), and the second is 10 (decimal).  There are no HOM blocks on the other units.
 The HOM block is one record, i.e. 128 words.  The ID strings are 8-bit ASCII, stored byte swapped in half words.
@@ Line 75: / Line 75: @@
 == BAT block ==
-The '''BAT''' block is after the first HOM block, and is optional.
+The '''BAT''' block is after the first HOM block, and is optional in the 1988 format.  The 1974 format has no BAT block.
 == SAT ==

@@ Line 91: / Line 91: @@
 == RIB ==
-All blocks start with a '''RIB''', ''retrieval information block''.  It's a record which holds information about the file the block belongs to.
+All blocks start with a '''RIB''', ''retrieval information block'', also called '''retrieval record'''.  It's a record which holds information about the file the block belongs to.
 == MFD ==