Heading:x2qjk40(635)
Mesa 6.0 System Updatey756x2qjk40\b22B
Page Numbers: Yes  X: 527  Y: 10.5"x2qjk40
Copyright c Xerox Corporation 1980z18592l4445y45c\10f3 1f0
Inter-Office Memorandumz18592l4445y762x2\f5b
To	Mesa Users	Date	October 27, 1980z18592l4445d2998x2e21(0,65535)(1,4445)(5,11684)(6,14146)\f7 2f0t2 1t0 10t6 1f7t0 4f0t7 1t0
From	John Wick	Location	Palo Altoz18592l4445d2998y716x2e25\f7 4f0t2 1t0 9t6 1f7t0 8f0t7 1t0
Subject	Mesa 6.0 System Update	Organization	SDD/SS/Mesaz18592l4445d2998x2e25\f7 7f0t2 1t0b22t6B1f7t0 12f0t7 1t0
XEROX       z18592l508y644x2e14(2116)\f2 5f0
Filed on: [Iris]<Mesa>Doc>System60.bravo (and .press)x2e30(0,16263)(1,65535)(5,65535)(6,65535)\f7 53f0
x2e10(2116)
This memo outlines changes made in the Mesa system interfaces since the last release (Mesa 5.0, April 9, 1979).  A number of internal changes made in the system and the microcode are also discussed.x2e12jk40
This memo is intended as a quick guide to conversion, not a detailed specification of the changes.  Names in square brackets refer to sections of the Mesa System Documentation or to other publicly available reference documents (e.g., the Alto Operating System Reference Manual).x2e12jk40\150i25I63i38I
External Interfacesx2e18jk60\b19B
Major changes include integrated support for Alto extended memory and elimination of BasicMesa.  The System also now exports versions of the following Development Software interfaces: Ascii, Format, Inline, Process, Runtime, Storage, String, System, and Time.  (Note that implementation of these interfaces may not be complete.)  Other changes are relatively minor.x2e12jk40\184f6b5f0B2f6b6f0B2f6b6f0B2f6b7f0B2f6b7f0B2f6b7f0B2f6b6f0B2f6b6f0B6f6b4f0B
AllocDefsx2e12jk60\i
Private types and operations have been removed.  AllocInfo, MakeDataSegment, and MakeSwappedIn are now defined in SegmentDefs, and temporarily duplicated here for compatibility. [Segment Package]x2e6jk40\49f6b9f0B2f6b15f0B6f6b13f0B20f6b11f0B54b15B
AltoDefsx2e12jk60\i
MaxVMPage has been increased to support up to a million words of memory; MaxMDSPage and PagesPerMDS have been added. [Segment Package]x2e6jk40\f6b9f0B64f6b10f0B5f6b11f0B19b15B
AltoDisplayx2e12jk60\i
MaxBitsPerLine has been changed to 608 (it was 606).  Cursor, CursorBits, and CursorHandle define the location and format of the cursor.  Coordinate, CursorXY, and MouseXY define the location and format of the cursor and mouse coordinates. [Display Package]x2e6jk40\f6b14f0B40f6b6f0B2f6b10f0B6f6b12f0B48f6b10f0B2f6b8f0B6f6b7f0B70b15B
AltoFileDefsx2e12jk60\i
Support for the DiskShape and PartitionName properties of the directory's leader page has been added.  The definition of a file serial number (SN) has been changed to isolate the flag bits (directory, random, and nolog) into a separate structure (SNBits). [Alto Operating System Reference Manual]x2e6jk40\16f6b9f0B5f6b13f0B100f6b2f0B45f6b9f0B2f6b6f0B6f6b5f0B29f6b6f0B4i38I
AltoHardwarex2e12jk60\i
This new interface defines most structures of the Alto hardware, including the processor, display, keyboard, mouse, keyset, printer interface, disk, and Ethernet. [Alto Hardware Manual]x2e6jk40\164i20I
Asciix2e12jk60\i
This new interface defines the ASCII control character codes; for compatibility, these continue to be defined in IODefs. [StreamIO Package]x2e6jk40\32f1 4f0 77f6b6f0B3b16B
BasicMesax2e12jk60\i
The facilities of BasicMesa have been replaced by procedures in the standard system and a command line switch (/b) which can be used to destroy the display and keyboard packages (see DisplayDefs and StreamDefs).  MakeImage is no longer a standard part of Mesa.image, and must be loaded separately. [Section 3]x2e6jk40\18f6b9f0B84f8 2f0 70f6b11f0B5f6b10f0B4f6b9f0B33f8 10f0 34b9B
BitBltDefsx2e12jk60\i
The extended memory option now supports use of the normal and alternate bank registers, whose values are supplied in the unused word of the BBTable (this option is not supported under XMesa 5.0 microcode (version 39)).  AlignedBBTable (and BBTableSpace) can be used to properly align BITBLT argument records. [Alto Hardware Manual]x2e6jk40\140f6b7f0B17i3I53f6b14f0B6f6b12f0B32f7b6f0B20i20I
CharIOx2e12jk60\i
This new interface provides many of the functions of IODefs, but each operation takes a StreamDefs.StreamHandle as its first parameter, allowing formatted input and output to any standard stream. [StreamIO Package]x2e6jk40\53f6b6f0B29f6b23f0B86b16B
DirectoryDefsx2e12jk60\i
This interface has been changed slightly to speed up directory searches (by about a factor of 3).  In addition, support for subdirectories was added (see Alto Operating System Reference Manual).  The following items have changed (note that a NIL DiskHandle does not imply the system directory):x2e6jk40\154i38I50f7 3f0 1f6b10f0B6i3I
EnumerateEntries: PROCEDURE [
  dir: DiskHandle,
  proc: PROCEDURE [CARDINAL, StreamScan.Handle, DEptr] RETURNS [BOOLEAN],
  inspectFree: POINTER TO READONLY BOOLEAN,
  lengthFilter: CARDINAL _ 0] RETURNS [index: CARDINAL];l4269x2e6k40\f6b18f7 9f6 30f7 9f6 2f7 8f6 28f7 7f6 2f7 7f6 18f7 27f6 18f7 8f6 6f7 7f6 9f7 8f6
The procedure proc is called for each directory entry; free entries are passed only if inspectFree^ is TRUE.  If the lengthFilter is non-zero, only entries with a filename length equal to lengthFilter characters will be passed to proc.x2e6jk40\14f6b4f0B69f6b12f0B4f7 4f0 10f6b12f0B59f6b12f0B30f6b4f0B
The following procedure inserts an entry into the directory; unlike Lookup, it does not create a file.  If the file already exists, TRUE is returned (and fp^ is undisturbed).x2e6jk40\68f6b6f0B58f7 4f0 18f6b3f0B
Insert: PROCEDURE [
  dir: DiskHandle, fp: POINTER TO AltoFileDefs.FP, name: STRING]
  RETURNS [old: BOOLEAN];l4269x2e6k40\f6b8f7 9f6 26f7 10f6 24f7 6f6 4f7 7f6 7f7 7f6
ParseFileName replaces ExpandFileName; it strips the leading directory information from name, puts the result in filename (appending a period if necessary), and returns a stream (with access dirAccess) open on the directory in which the file should be looked up.x2e6jk40\f6b13f0B10f6b14f0B51f6b4f0B21f6b8f0B70f6b9f0B
ParseFileName: PROCEDURE [
  name, filename: STRING, dirAccess: SegmentDefs.AccessOptions]
  RETURNS [StreamDefs.DiskHandle];l4269x2e6k40\f6b15f7 9f6 21f7 6f6 42f7 7f6
The following procedures set and return the directory used for looking up files which do not specify a directory name (initially set to "<SysDir.").x2e6jk40\136f8 10f0
SetWorkingDir: PROCEDURE [dir: SegmentDefs.FileHandle];l4269x2e6k40\f6b15f7 9f6
GetWorkingDir: PROCEDURE RETURNS [dir: SegmentDefs.FileHandle];l4269x2e6k40\f6b15f7 17f6
Finally, the signal BadDirectory no longer takes a string parameter. [Directory Package, Alto Operating System Reference Manual]x2e6jk40\20f6b12f0B38b17B2i38I
DisplayDefsx2e12jk80\i
DestroyDisplay can be used to delete the display package; it turns off the display, deallocates the bitmap, destroys the font, and UNNEWs all the display modules. [Display Package]x2e6jk40\f6b14f0B117f7 5f0 28b15B
DoubleDefsx2e12jk60\i
This interface is no longer implemented or supported, since LONG data types are now a standard part of the language and runtime support.x2e6jk40\60f7b4f0B
FrameDefsx2e12jk60\i9I
Validate(Global)Frame and Invalid(Global)Frame now take (return) UNSPECIFIED.  The procedurex2e12jk40\f6b21f0B5f6b20f0B19f7b11f0B
LoadConfig: PROCEDURE [name: STRING] RETURNS [PROGRAM];l4269x2e6k40\f6b12f7 9f6 8f7 6f6 2f7 7f6 2f7 7f6
loads a configuration without starting it and returns its control module or control module list (or NIL if there is no control module).  Note that this will not handle configurations whose control modules take parameters. [Modules]x2e12jk40\100f7 3f0 120b7B
FSPDefsx2e12jk60\i7I
The error ZoneTooLarge is now raised by Make(New)Zone and AddTo(New)Zone when an attempt is made to make a zone of more than 32K words.  [Storage Management]x2e12jk40\10f6b12f0B18f6b13f0B5f6b14f0B66b18B
ImageDefsx2e12jk60\i
MakeImage takes an optional second parameter (merge: BOOLEAN _ TRUE); MakeUnMergedImage has been temporarily retained for compatibility.  The ImageMaker package is no longer a part of the standard system; it must be loaded or bound with the client configuration. [Image Files]x2e6jk40\f6b9f0B37f6b7f7 7f6 3f7 4f0B3f6b17f0B55f6b10f0B112b11B
InlineDefsx2e12jk60\i
The LongCOPY operation for use with long pointers is now implemented by the extended memory microcode.  The types BytePair and BcplLongNumber have been added; the procedures MesaToBcplLongNumber and BcplToMesaLongNumber implement conversion between Mesa and BCPL long numbers. [Miscellaneous]x2e6jk40\4f6b8f0B102f6b8f0B5f6b14f0B33f6b20f0B5f6b20f0B40f1 3f0 16b13B
IODefsx2e12jk60\i
The procedure WriteSubString has been added. [StreamIO Package]x2e6jk40\14f6b14f0B18b16B
MiscDefsx2e12jk60\i8I
The ByteBlt procedure has been added. [Miscellaneous]x2e6jk40\4f6b7f0B28b13B
MiscOpsx2e12jk60\i7I
ReleaseDebuggerBitmap can be used to free the storage normally allocated (on extended memory machines) for the Debugger's bitmap. [Section 3]x2e6jk40\f6b21f0B110b9B
OsStaticDefsx2e12jk60\i12I
The type of ClockSecond has been changed to use InlineDefs.BcplLongNumber. [Alto Operating System Reference Manual]x2e6jk40\12f6b11f0B25f6b25f0B3i38I
ProcessDefsx2e12jk60\i11I
Aborted has been redefined to be equal to the predeclared error ABORTED.  A Pause procedure has been added which delays execution of its caller by the specified number of ticks.  Detach and GetCurrent now take (return) a PROCESS instead of an UNSPECIFIED. [Processes and Monitors]x2e6jk40\f6b7f0B57f7 7f0 5f6b5f0B98f6b6f0B5f6b10f0B21f7b7f0B15f7b11f0B3b22B
SegmentDefsx2e12jk60\i11I
The majority of changes in SegmentDefs are due to the incorporation of XMesa and extended memory support into the standard system.  Clients of XMesa should see the XMesa update document.x2e6jk40\27f6b11f0B
The definition of SegmentObjects has changed to allow for a twelve bit page number.  The read bit in FileSegmentObjects has been deleted (read access is always assumed) and MaxSegLocks has been reduced to fifteen (MaxSegLocks and MaxFileLocks replace MaxLocks).x2e6jk40\18f6b14f0B57f6b4f0B8f6b18f0B54f6b11f0B30f6b11f0B5f6b12f0B9f6b8f0B
A type field has been added to DataSegmentObjects with predefined values UnknownDS, FrameDS, TableDS, HeapDS, SystemDS, BitmapDS, StreamBufferDS, and PupBufferDS.  These types are interpreted by the Debugger's Coremap command.x2e6jk40\31f6b17f0B25f6b9f0B2f6b7f0B2f6b7f0B2f6b6f0B2f6b8f0B2f6b8f0B2f6b14f0B6f6b11f0B49f8 7f0
For clients of low level memory allocation, the definition of AllocInfo has changed and the constants HardUp, HardDown, EasyUp, and EasyDown have been defined.  The procedures MakeDataSegment and MakeSwappedIn have been moved here from AllocDefs.x2e6jk40\62f6b9f0B31f6b6f0B2f6b8f0B2f6b6f0B6f6b8f0B36f6b15f0B5f6b13f0B27f6b9f0B
The  access options ReadWrite, WriteAppend and ReadWriteAppend have been added.  NewFile and InsertFile now default the access and version parameters.x2e6jk40\20f6b9f0B2f6b11f0B5f6b15f0B19f6b7f0B5f6b10f0B17f6b6f0B5f6b7f0B
The following two procedures have been added to provide access to file times:x2e6jk40
GetFileTimes: PROCEDURE [file: FileHandle]
  RETURNS [read, write, create: TimeDefs.PackedTime];l4269x2e6k40\f6b14f7 9f6 22f7 7f6
SetFileTimes: PROCEDURE [
  file: FileHandle,
  read, write, create: TimeDefs.PackedTime _ TimeDefs.DefaultTime];l4269x2e6k40\f6b14f7 9f6
GetFileTimes does not modify any of the file's times.  In SetFileTimes, if any of the times are defaulted, the current time is used. [Segment Package]x2e6jk40\f6b12f0B46f6b12f0B64b15B
StreamDefsx2e12jk60\i10I
DestroyKeyHandler can be used to delete the standard keyboard handler; it destroys the keyboard process and UNNEWs all the keyboard modules. [Keyboard]x2e6jk40\f6b17f0B91f7 5f0 29b8B
The type StreamPosition, defined as a LONG CARDINAL, can be used in place of a StreamIndex.  The operations GetPosition, SetPosition, and ModifyPosition are similar to the corresponding index operations; IndexToPosition and PositionToIndex perform conversions between positions and indicies.  The access options ReadWrite, WriteAppend, and ReadWriteAppend have been added, as has the signal FileNameError. [Disk Streams]x2e6jk40\9f6b14f0B15f7b13f0B28f6b11f0B18f6b11f0B2f6b11f0B6f6b14f0B52f6b15f0B5f6b15f0B73f6b9f0B2f6b11f0B6f6b15f0B36f6b13f0B3b12B
StreamScanx2e12jk60\i10I
This new interface allows overlapped disk input when reading from a stream.  It is a transliteration of the same code from the Alto Operating System (version 17).  The following are defined in StreamScan.mesa:x2e6jk40
Descriptor: TYPE = RECORD [
  da: AltoFileDefs.vDA,
  pageNumber: CARDINAL,
  numChars: CARDINAL,
  -- private fields];l4269x2e6k40\f6b12f7 4f6 3f7 6f6 41f7 8f6 14f7 8f6 4Bi17bI
Handle: TYPE = POINTER TO READONLY Descriptor;l4269x2e6k40\f6b8f7 4f6 3f7 19f6
Init: PROCEDURE [
  stream: StreamDefs.StreamHandle, bufTable: POINTER, nBufs: CARDINAL]
  RETURNS [Handle];l4269x2e6k40\f6b6f7 9f6 48f7 7f6 9f7 8f6 4f7 7f6
GetBuffer: PUBLIC PROCEDURE [ssd: Handle] RETURNS [POINTER];l4269x2e6k40\f6b11f7 16f6 15f7 7f6 2f7 7f6
Finish: PROCEDURE [ssd: Handle];l4269x2e6k40\f6b8f7 9f6
Init sets up a scan stream from a disk stream.  In addition to the stream, the client supplies a vector of pointers to 256 word areas useable as disk buffers (bufTable).  The number of buffers supplied is nBufs.  At least one buffer must be supplied (the normal stream buffer is also used).  Each call to GetBuffer will return a pointer to the next sequential page of the file and returns the previous buffer page to the buffer pool (first call returns data page 0; file page 1).  The public fields of the Handle are correct for the page returned by the most recent call to GetBuffer.  GetBuffer returns NIL when there are no more pages to be read.  A call to Finish terminates the scan.  No other stream operations should be performed between Init and Finish. [Disk Streams Package]x2e6jk40\f6b4f0B155f6b8f0B38f6b5f0B95f6b9f0B192f6b6f0B62f6b9f0B3f6b9f0B9f7b3f0B53f6b6f0B78f6b4f0B5f6b6f0B3b20B1f6b
StringDefsx2e12jk60\i10I
CompareStrings lexically compares two strings and returns -1, 0, or 1 if the first is less than, equal to, or greater than the second; an optional parameter may be supplied to ignore case differences.  All procedures in this interface now handle NIL string parameters. [String Package]x2e6jk40\f6b14f0B232f7 3f0 21b14B
SystemDefsx2e12jk60\i10I
CopyString allocates storage from the system heap and copies its argument into it, optionally making the new string longer.  ExpandString performes a similar function, allocating a new string (and freeing the old one) if necessary.  Even and Quad can be used to align pointers on double and quad word boundaries. [Storage Management]x2e6jk40\f6b10f0B115f6b12f0B96f6b4f0B5f6b4f0B68b18B
TimeDefsx2e12jk60\i8I
The type HardwareTime has been replaced by InlineDefs.BcplLongNumber.   Default values have been added to UnpackDT, PackDT, and AppendDayTime.  ReadClock returns the current value of the Alto's realtime clock (part of which can be found at location RealTimeClock). [Time Package]x2e6jk24\9f6b12f0B22f6b25f0B38f6b8f0B2f6b6f0B6f6b13f0B3f6b9f0B96f6b13f0B4b12B
TrapDefsx2e12jk60\i8I
StackError no longer takes a parameter; UnboundProcedure now takes an UNSPECIFIED.  The following signals have been added (not all of which can be generated by Alto/Mesa): ZeroDivisor, DivideCheck, UnimplementedInst, WakeupError, PageFault, Write-ProtectFault, and HardwareError. [Traps]x2e6jk40\f6b10f0B30f6b16f0B14f7b11f0B91f6b11f0B2f6b11f0B2f6b17f0B2f6b11f0B2f6b9f0B2f6b18f0B6f6b13f0B3b5B
XMesa Extended Memory Supportx2e12jk60\i29I
Functions formerly provided by XMesa are now integrated with the standard system.  A 3K RAM or Mesa microcode in ROM1 is required to support the extended memory option. [Segment Package]x2e6jk40\88f1 3f0 22f1 4f0 53b15B
Internal Interfacesx2e18jk80\b19B
The following changes are internal to the implementation and do not affect public interfaces; they may affect performance and/or space requirements, however.  Note that Mesa 6.0 continues to support version 39 of the XMesa microcode available with Mesa 5.0; obviously, certain new features listed below are not available if your ROM contains the old microcode (e.g., Long BitBlt).x2e12jk60\329f1 3f0
3K RAM Supportx2e12jk60\i
Mesa now supports the Alto 3K RAM option (available only on extended memory machines).x2e6jk40\30f1 3f0 53i
Debugger Bitmapx2e12jk60\i
If the extended memory option is present, the system allocates part of the client's memory for use by the debugger for its display bitmap; this improves the debugger's response times considerably.   The debugger bitmap may be deallocated by the procedure MiscOps.ReleaseDebuggerBitmap or the command line switch /k (in the former case, the call must be made before the debugger is first entered).x2e6jk40\255f6b29f0B28f8 2f0 82i
Long Copy, Long BitBltx2e12jk60\i
These opcodes now include support for extended memory.x2e6jk40\54i
Misc Opcodesx2e12jk80\i
Misc opcodes (except for RCLK) now provide a general escape to user microcode in the RAM if Mesa is running on a 2K ROM or 3K RAM machine; they produce undefined results otherwise.  Alpha bytes for the currently implemented MISC functions are defined in MiscAlpha.x2e6jk40\25f7b4f0B56f1 3f0 28f1 3f0 7f1 3f0 95f7 4f0 26f6b9f0B1i
Overflow Microcodex2e12jk60\i
RunMesa has been upgraded to include microcode support for Pup checksums, IEEE floating point, and HBlt (used by Griffin).  This microcode is loaded with the XMesa overflow microcode on Altos with the 2K ROM (with version 41 microcode) or 3K RAM option.  Users who have been loading microcode for these functions need no longer do so.  This change affects Alto IIs only.x2e6jk40\204f1 3f0 35f1 3f0 125i
Range Checkingx2e12jk60\i
The bounds check instruction (BNDCK) is now implemented correctly.x2e6jk40\30f7b5f0B
x2e12jk40
Distribution:
Mesa Users
Mesa Group
SDSupportl3528d2998x2e12j
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